Merge pull request #2590 from Kenpachi2k13/issue#2530

Change unload NPC behavior to kill mobs that were spawned by unloaded NPC (non-permanent monster spawns) [Issue #2530]

20 files changed, 1136 insertions, 685 deletions

diff --git a/conf/messages.conf b/conf/messages.conf
index 787498e8e..e297c4fa5 100644
--- a/conf/messages.conf
+++ b/conf/messages.conf
@@ -1016,8 +1016,8 @@
 // @loadnpc
 1132: Please enter a script file name (usage: @loadnpc <file name>).
 
-// @npcoff
-1133: Please enter a NPC name (usage: @npcoff <NPC_name>).
+// @unloadnpc
+1133: Please enter a NPC name (Usage: @unloadnpc <NPC_name> {<flag>}).
 
 // @jail
 1134: Please enter a player name (usage: @jail <char_name>).
@@ -1455,8 +1455,8 @@
 1384: User '%s' permissions updated successfully. The changes are temporary.
 
 // @unloadnpcfile
-1385: Usage: @unloadnpcfile <file name>
-1386: File unloaded. Be aware that mapflags and monsters spawned directly are not removed.
+1385: Usage: @unloadnpcfile <path> {<flag>}
+1386: File unloaded. Be aware that some changes made by NPC are not reverted on unload. See doc/atcommands.txt for details.
 1387: File not found.
 
 // General command messages
@@ -1636,5 +1636,13 @@
 1514: %d: Refine All Equip (Costume)
 1515: %d: Refine All Equip (Shadow)
 
+// @reloadnpc
+1516: Usage: @reloadnpc <path> {<flag>}
+1517: Script could not be unloaded.
+
+// File name validation
+1518: Not a file.
+1519: Can't open file.
+
 //Custom translations
 import: conf/import/msg_conf.txt
diff --git a/doc/atcommands.txt b/doc/atcommands.txt
index 419cb0acd..0cddc1680 100644
--- a/doc/atcommands.txt
+++ b/doc/atcommands.txt
@@ -1273,31 +1273,47 @@ Example:
 
 ---------------------------------------
 
-@unloadnpc <npc name>
-
-Unloads an NPC.
+@unloadnpc <NPC_name> {<flag>}
+
+Unloads a NPC.
+Flag:
+	0 - do not unload mobs spawned by NPCs in file
+	1 - unload mobs spawned by NPCs in file
+	Default is 1; every number other than 0 will be treaten as 1.
+	Mobs that were spawned with monster/areamonster/guardian/bg_monster/atcommand("@monster xy") are affected.
+Note:
+	Be aware that some changes made by NPC are not reverted on unload.
+	Please use the OnNPCUnload label to clean things up by yourself. Commonly relevant for these script commands:
+	-> setmapflagnosave, setmapflag, removemapflags, setbattleflag, setcell, setwall
+	-> agitstart/agitstart2, agitend/agitend2, gvgon, gvgoff, pvpon, pvpoff
+	-> addmonsterdrop, setitemscript, npcshopitem, npcshopadditem, npcshopdelitem, hateffect, disguise
+	-> pcfollow, pcblockmove, setpcblock, setnpcdir, navigateto, viewpoint, add_group_command, skill/addtoskill
+	-> instance and battleground related stuff (excepting bg_monster)
 
 Example:
-@unloadnpc Job Master
+@unloadnpc Job Master 0
 
 ---------------------------------------
 
-@unloadnpcfile <path>
+@unloadnpcfile <path> {<flag>}
 
 Unloads all NPCs in a file.
+Flag: See @unloadnpc
+Note: See @unloadnpc
 
 Example:
-@unloadnpcfile npc/custom/jobmaster.txt
+@unloadnpcfile npc/custom/jobmaster.txt 0
 
 ---------------------------------------
 
-@reloadnpc <path>
+@reloadnpc <path> {<flag>}
 
 Unloads all NPCs in a file and reload it again.
-Note: Be aware that mapflags and monsters spawned directly are not removed.
+Flag: See @unloadnpc
+Note: See @unloadnpc
 
 Example:
-@reloadnpc npc/custom/jobmaster.txt
+@reloadnpc npc/custom/jobmaster.txt 0
 
 ---------------------------------------
 
diff --git a/doc/script_commands.txt b/doc/script_commands.txt
index 6a97bae1d..1914285f0 100644
--- a/doc/script_commands.txt
+++ b/doc/script_commands.txt
@@ -1034,6 +1034,11 @@ will only execute once and will not execute if the map server reconnects
 to the char server later. Note that all those events will be executed upon
 scripts reloading.
 
+OnNPCUnload:
+
+OnNPCUnload will be executed when a NPC is unloaded.
+OnNPCUnload is called when @reloadscript, @reloadnpc, @unloadnpc or @unloadnpcfile is used.
+
 OnAgitStart:
 OnAgitEnd:
 OnAgitInit:
diff --git a/src/common/utils.c b/src/common/utils.c
index 48ce539b6..084080df7 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -132,7 +132,7 @@ void findfile(const char *p, const char *pat, void (func)(const char *, void *co
 {
 	WIN32_FIND_DATAA FindFileData;
 	HANDLE hFind;
-	char tmppath[MAX_PATH+1];
+	char tmppath[MAX_DIR_PATH + 1];
 	const char *path    = (p  ==NULL)? "." : p;
 	const char *pattern = (pat==NULL)? "" : pat;
 
@@ -166,9 +166,26 @@ void findfile(const char *p, const char *pat, void (func)(const char *, void *co
 	}
 	return;
 }
-#else
 
-#define MAX_DIR_PATH 2048
+/**
+ * Checks if the passed path points to a file.
+ *
+ * @param path The path which should be checked.
+ * @return true if the passed path points to a file, otherwise false.
+ *
+ **/
+bool is_file(const char *path)
+{
+	nullpo_retr(false, path);
+
+	char path_tmp[MAX_DIR_PATH + 1];
+
+	checkpath(path_tmp, path);
+
+	return ((GetFileAttributesA(path_tmp) & FILE_ATTRIBUTE_DIRECTORY) == 0);
+}
+
+#else
 
 static char *checkpath(char *path, const char *srcpath)
 {
@@ -235,6 +252,27 @@ void findfile(const char *p, const char *pat, void (func)(const char *, void *co
 
 	closedir(dir);
 }
+
+/**
+ * Checks if the passed path points to a file.
+ *
+ * @param path The path which should be checked.
+ * @return true if the passed path points to a file, otherwise false.
+ *
+ **/
+bool is_file(const char *path)
+{
+	nullpo_retr(false, path);
+
+	char path_tmp[MAX_DIR_PATH + 1];
+
+	checkpath(path_tmp, path);
+
+	struct stat path_stat;
+
+	return (stat(path_tmp, &path_stat) == 0 && S_ISREG(path_stat.st_mode));
+}
+
 #endif
 
 bool exists(const char *filename)
diff --git a/src/common/utils.h b/src/common/utils.h
index a0590db7f..3e0d73e40 100644
--- a/src/common/utils.h
+++ b/src/common/utils.h
@@ -31,6 +31,14 @@
 /* [HCache] 1-byte key to ensure our method is the latest, we can modify to ensure the method matches */
 #define HCACHE_KEY 'k'
 
+#ifndef MAX_DIR_PATH
+#ifdef WIN32
+#define MAX_DIR_PATH MAX_PATH
+#else
+#define MAX_DIR_PATH 2048
+#endif
+#endif
+
 //Caps values to min/max
 #define cap_value(a, min, max) (((a) >= (max)) ? (max) : ((a) <= (min)) ? (min) : (a))
 
@@ -40,6 +48,7 @@ void WriteDump(FILE* fp, const void* buffer, size_t length);
 void ShowDump(const void* buffer, size_t length);
 
 void findfile(const char *p, const char *pat, void (func)(const char *, void *), void *context);
+bool is_file(const char *path);
 bool exists(const char* filename);
 
 /// calculates the value of A / B, in percent (rounded down)
diff --git a/src/map/atcommand.c b/src/map/atcommand.c
index 5d95e2c14..c9191d27d 100644
--- a/src/map/atcommand.c
+++ b/src/map/atcommand.c
@@ -4483,59 +4483,90 @@ ACMD(loadnpc)
 	return true;
 }
 
+/**
+ * Unloads a specific NPC.
+ *
+ * @code{.herc}
+ *	@unloadnpc <NPC_name> {<flag>}
+ * @endcode
+ *
+ **/
 ACMD(unloadnpc)
 {
-	struct npc_data *nd;
-	char NPCname[NAME_LENGTH+1];
-
-	memset(NPCname, '\0', sizeof(NPCname));
+	char npc_name[NAME_LENGTH + 1] = {'\0'};
+	int flag = 1;
 
-	if (!*message || sscanf(message, "%24[^\n]", NPCname) < 1) {
-		clif->message(fd, msg_fd(fd,1133)); // Please enter a NPC name (usage: @npcoff <NPC_name>).
+	if (*message == '\0' || sscanf(message, "%24s %1d", npc_name, &flag) < 1) {
+		clif->message(fd, msg_fd(fd, 1133)); /// Please enter a NPC name (Usage: @unloadnpc <NPC_name> {<flag>}).
 		return false;
 	}
-
-	if ((nd = npc->name2id(NPCname)) == NULL) {
-		clif->message(fd, msg_fd(fd,111)); // This NPC doesn't exist.
+	
+	struct npc_data *nd = npc->name2id(npc_name);
+	
+	if (nd == NULL) {
+		clif->message(fd, msg_fd(fd, 111)); /// This NPC doesn't exist.
 		return false;
 	}
 
-	npc->unload_duplicates(nd);
-	npc->unload(nd,true);
+	npc->unload_duplicates(nd, (flag != 0));
+	npc->unload(nd, true, (flag != 0));
 	npc->read_event_script();
-	clif->message(fd, msg_fd(fd,112)); // Npc Disabled.
+	clif->message(fd, msg_fd(fd, 112)); /// Npc Disabled.
 	return true;
 }
 
-/// Unload existing NPC within the NPC file and reload it.
-/// Usage: @reloadnpc npc/sample_npc.txt
+/**
+ * Unloads a script file and reloads it.
+ * Note: Be aware that some changes made by NPC are not reverted on unload. See doc/atcommands.txt for details.
+ *
+ * @code{.herc}
+ *	@reloadnpc <path> {<flag>}
+ * @endcode
+ *
+ **/
 ACMD(reloadnpc)
 {
-	if (!*message) {
-		clif->message(fd, msg_fd(fd, 1385)); // Usage: @unloadnpcfile <file name>
+	char format[20];
+
+	snprintf(format, sizeof(format), "%%%ds %%1d", MAX_DIR_PATH);
+
+	char file_path[MAX_DIR_PATH + 1] = {'\0'};
+	int flag = 1;
+
+	if (*message == '\0' || (sscanf(message, format, file_path, &flag) < 1)) {
+		clif->message(fd, msg_fd(fd, 1516)); /// Usage: @reloadnpc <path> {<flag>}
 		return false;
-	} else if (npc->unloadfile(message) == true) {
-		clif->message(fd, msg_fd(fd, 1386)); // File unloaded. Be aware that mapflags and monsters spawned directly are not removed.
+	}
 
-		FILE *fp = fopen(message, "r");
-		// check if script file exists
-		if (fp == NULL) {
-			clif->message(fd, msg_fd(fd, 261));
-			return false;
-		}
-		fclose(fp);
+	if (!exists(file_path)) {
+		clif->message(fd, msg_fd(fd, 1387)); /// File not found.
+		return false;
+	}
+
+	if (!is_file(file_path)) {
+		clif->message(fd, msg_fd(fd, 1518)); /// Not a file.
+		return false;
+	}
 
-		// add to list of script sources and run it
-		npc->addsrcfile(message);
-		npc->parsesrcfile(message, true);
-		npc->read_event_script();
+	FILE *fp = fopen(file_path, "r");
 
-		clif->message(fd, msg_fd(fd, 262));
-	} else {
-		clif->message(fd, msg_fd(fd, 1387)); // File not found.
+	if (fp == NULL) {
+		clif->message(fd, msg_fd(fd, 1519)); /// Can't open file.
 		return false;
 	}
 
+	fclose(fp);
+
+	if (!npc->unloadfile(file_path, (flag != 0))) {
+		clif->message(fd, msg_fd(fd, 1517)); /// Script could not be unloaded.
+		return false;
+	}
+
+	clif->message(fd, msg_fd(fd, 1386)); /// File unloaded. Be aware that...
+	npc->addsrcfile(file_path);
+	npc->parsesrcfile(file_path, true);
+	npc->read_event_script();
+	clif->message(fd, msg_fd(fd, 262)); /// Script loaded.
 	return true;
 }
 
@@ -6576,47 +6607,52 @@ ACMD(reset)
 /*==========================================
  *
  *------------------------------------------*/
+
+/**
+ * Spawns mobs which treats the invoking as its master.
+ *
+ * @code{.herc}
+ *	@summon <monster name/ID> {<duration>}
+ * @endcode
+ *
+ **/
 ACMD(summon)
 {
-	char name[NAME_LENGTH];
-	int mob_id = 0;
+	char name[NAME_LENGTH + 1] = {'\0'};
 	int duration = 0;
-	struct mob_data *md;
-	int64 tick=timer->gettick();
 
-	if (!*message || sscanf(message, "%23s %12d", name, &duration) < 1)
-	{
-		clif->message(fd, msg_fd(fd,1225)); // Please enter a monster name (usage: @summon <monster name> {duration}).
+	if (*message == '\0' || sscanf(message, "%24s %12d", name, &duration) < 1) {
+		clif->message(fd, msg_fd(fd, 1225)); /// Please enter a monster name (usage: @summon <monster name> {duration}).
 		return false;
 	}
 
-	if (duration < 1)
-		duration =1;
-	else if (duration > 60)
-		duration =60;
+	int mob_id = atoi(name);
 
-	if ((mob_id = atoi(name)) == 0)
+	if (mob_id == 0)
 		mob_id = mob->db_searchname(name);
-	if(mob_id == 0 || mob->db_checkid(mob_id) == 0)
-	{
-		clif->message(fd, msg_fd(fd,40)); // Invalid monster ID or name.
+
+	if (mob_id == 0 || mob->db_checkid(mob_id) == 0) {
+		clif->message(fd, msg_fd(fd, 40)); /// Invalid monster ID or name.
 		return false;
 	}
 
-	md = mob->once_spawn_sub(&sd->bl, sd->bl.m, -1, -1, DEFAULT_MOB_JNAME, mob_id, "", SZ_SMALL, AI_NONE);
+	struct mob_data *md = mob->once_spawn_sub(&sd->bl, sd->bl.m, -1, -1, DEFAULT_MOB_JNAME, mob_id, "",
+						  SZ_SMALL, AI_NONE, 0);
 
-	if(!md)
+	if (md == NULL)
 		return false;
 
 	md->master_id = sd->bl.id;
 	md->special_state.ai = AI_ATTACK;
-	md->deletetimer = timer->add(tick+(duration*60000),mob->timer_delete,md->bl.id,0);
-	clif->specialeffect(&md->bl,344,AREA);
-	mob->spawn(md);
-	sc_start4(NULL,&md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 60000);
-	clif->skill_poseffect(&sd->bl,AM_CALLHOMUN,1,md->bl.x,md->bl.y,tick);
-	clif->message(fd, msg_fd(fd,39)); // All monster summoned!
 
+	const int64 tick = timer->gettick();
+
+	md->deletetimer = timer->add(tick + (int64)cap_value(duration, 1, 60) * 60000, mob->timer_delete, md->bl.id, 0);
+	clif->specialeffect(&md->bl, 344, AREA);
+	mob->spawn(md);
+	sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 60000);
+	clif->skill_poseffect(&sd->bl, AM_CALLHOMUN, 1, md->bl.x, md->bl.y, tick);
+	clif->message(fd, msg_fd(fd, 39)); /// All monster summoned!
 	return true;
 }
 
@@ -9009,19 +9045,54 @@ ACMD(addperm)
 	return true;
 }
 
+/**
+ * Unloads a script file.
+ * Note: Be aware that some changes made by NPC are not reverted on unload. See doc/atcommands.txt for details.
+ *
+ * @code{.herc}
+ *	@unloadnpcfile <path> {<flag>}
+ * @endcode
+ *
+ **/
 ACMD(unloadnpcfile)
 {
-	if (!*message) {
-		clif->message(fd, msg_fd(fd,1385)); // Usage: @unloadnpcfile <file name>
+	char format[20];
+
+	snprintf(format, sizeof(format), "%%%ds %%1d", MAX_DIR_PATH);
+
+	char file_path[MAX_DIR_PATH + 1] = {'\0'};
+	int flag = 1;
+
+	if (*message == '\0' || (sscanf(message, format, file_path, &flag) < 1)) {
+		clif->message(fd, msg_fd(fd, 1385)); /// Usage: @unloadnpcfile <path> {<flag>}
 		return false;
 	}
 
-	if (npc->unloadfile(message)) {
-		clif->message(fd, msg_fd(fd,1386)); // File unloaded. Be aware that mapflags and monsters spawned directly are not removed.
-	} else {
-		clif->message(fd, msg_fd(fd,1387)); // File not found.
+	if (!exists(file_path)) {
+		clif->message(fd, msg_fd(fd, 1387)); /// File not found.
 		return false;
 	}
+
+	if (!is_file(file_path)) {
+		clif->message(fd, msg_fd(fd, 1518)); /// Not a file.
+		return false;
+	}
+
+	FILE *fp = fopen(file_path, "r");
+
+	if (fp == NULL) {
+		clif->message(fd, msg_fd(fd, 1519)); /// Can't open file.
+		return false;
+	}
+
+	fclose(fp);
+
+	if (!npc->unloadfile(file_path, (flag != 0))) {
+		clif->message(fd, msg_fd(fd, 1517)); /// Script could not be unloaded.
+		return false;
+	}
+
+	clif->message(fd, msg_fd(fd, 1386)); /// File unloaded. Be aware that...
 	return true;
 }
 
diff --git a/src/map/atcommand.h b/src/map/atcommand.h
index f3b1be51b..66827b3b2 100644
--- a/src/map/atcommand.h
+++ b/src/map/atcommand.h
@@ -41,7 +41,7 @@ struct config_setting_t;
  * Defines
  **/
 #define ATCOMMAND_LENGTH 50
-#define MAX_MSG 1516
+#define MAX_MSG 1520
 #define msg_txt(idx) atcommand->msg(idx)
 #define msg_sd(sd,msg_number) atcommand->msgsd((sd),(msg_number))
 #define msg_fd(fd,msg_number) atcommand->msgfd((fd),(msg_number))
diff --git a/src/map/clif.c b/src/map/clif.c
index d41a17e0b..868117a96 100644
--- a/src/map/clif.c
+++ b/src/map/clif.c
@@ -15280,8 +15280,8 @@ static void clif_parse_GMKick(int fd, struct map_session_data *sd)
 				clif->GM_kickack(sd, 0);
 				return;
 			}
-			npc->unload_duplicates(nd);
-			npc->unload(nd,true);
+			npc->unload_duplicates(nd, true);
+			npc->unload(nd, true, true);
 			npc->read_event_script();
 		}
 		break;
diff --git a/src/map/instance.c b/src/map/instance.c
index 90f2217b1..1104b7e88 100644
--- a/src/map/instance.c
+++ b/src/map/instance.c
@@ -446,7 +446,7 @@ static int instance_cleanup_sub(struct block_list *bl, va_list ap)
 			map->quit(BL_UCAST(BL_PC, bl));
 			break;
 		case BL_NPC:
-			npc->unload(BL_UCAST(BL_NPC, bl), true);
+			npc->unload(BL_UCAST(BL_NPC, bl), true, true);
 			break;
 		case BL_MOB:
 			unit->free(bl,CLR_OUTSIGHT);
diff --git a/src/map/map.c b/src/map/map.c
index 9a45c4d21..8b52fc761 100644
--- a/src/map/map.c
+++ b/src/map/map.c
@@ -6092,7 +6092,7 @@ static int cleanup_sub(struct block_list *bl, va_list ap)
 			map->quit(BL_UCAST(BL_PC, bl));
 			break;
 		case BL_NPC:
-			npc->unload(BL_UCAST(BL_NPC, bl), false);
+			npc->unload(BL_UCAST(BL_NPC, bl), false, true);
 			break;
 		case BL_MOB:
 			unit->free(bl,CLR_OUTSIGHT);
diff --git a/src/map/mob.c b/src/map/mob.c
index 4b74abc8f..6c1076114 100644
--- a/src/map/mob.c
+++ b/src/map/mob.c
@@ -337,15 +337,23 @@ static int mob_parse_dataset(struct spawn_data *data)
 
 	return 1;
 }
-/*==========================================
- * Generates the basic mob data using the spawn_data provided.
- *------------------------------------------*/
-static struct mob_data *mob_spawn_dataset(struct spawn_data *data)
+
+/**
+ * Generates basic mob data by using the passed spawn data.
+ *
+ * @param data The mobs spawn data.
+ * @param npc_id If spawned by NPC script, this holds the ID of the invoking NPC.
+ * @return The generated mob data, later used to spawn the mob.
+ *
+ **/
+static struct mob_data *mob_spawn_dataset(struct spawn_data *data, int npc_id)
 {
-	struct mob_data *md = NULL;
 	nullpo_retr(NULL, data);
-	CREATE(md, struct mob_data, 1);
-	md->bl.id= npc->get_new_npc_id();
+
+	struct mob_data *md = (struct mob_data *)aCalloc(1, sizeof(struct mob_data));
+
+	memcpy(md->name, data->name, NAME_LENGTH);
+	md->bl.id = npc->get_new_npc_id();
 	md->bl.type = BL_MOB;
 	md->bl.m = data->m;
 	md->bl.x = data->x;
@@ -353,24 +361,29 @@ static struct mob_data *mob_spawn_dataset(struct spawn_data *data)
 	md->class_ = data->class_;
 	md->state.boss = data->state.boss;
 	md->db = mob->db(md->class_);
+	md->npc_id = npc_id;
+	md->spawn_timer = INVALID_TIMER;
+	md->deletetimer = INVALID_TIMER;
+	md->skill_idx = -1;
+
 	if (data->level > 0 && data->level <= MAX_LEVEL)
 		md->level = data->level;
-	memcpy(md->name, data->name, NAME_LENGTH);
-	if (data->state.ai)
+
+	if (data->state.ai > 0)
 		md->special_state.ai = data->state.ai;
-	if (data->state.size)
+
+	if (data->state.size > 0)
 		md->special_state.size = data->state.size;
-	if (data->eventname[0] && strlen(data->eventname) >= 4)
+
+	if (data->eventname[0] != '\0' && strlen(data->eventname) >= 4)
 		memcpy(md->npc_event, data->eventname, 50);
-	if(md->db->status.mode&MD_LOOTER)
-		md->lootitem = (struct item *)aCalloc(LOOTITEM_SIZE,sizeof(struct item));
-	md->spawn_timer = INVALID_TIMER;
-	md->deletetimer = INVALID_TIMER;
-	md->skill_idx = -1;
+
+	if ((md->db->status.mode & MD_LOOTER) == MD_LOOTER)
+		md->lootitem = (struct item *)aCalloc(LOOTITEM_SIZE, sizeof(struct item));
+
 	status->set_viewdata(&md->bl, md->class_);
 	status->change_init(&md->bl);
 	unit->dataset(&md->bl);
-
 	map->addiddb(&md->bl);
 	return md;
 }
@@ -503,7 +516,24 @@ static bool mob_ksprotected(struct block_list *src, struct block_list *target)
 	return false;
 }
 
-static struct mob_data *mob_once_spawn_sub(struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai)
+/**
+ * Prepares a mob's spawn data.
+ *
+ * @param bl The invoking character's block list.
+ * @param m The ID of the map where the mob should be spawned.
+ * @param x The x coordinate where the mob should be spawned.
+ * @param y The y coordinate where the mob should be spawned.
+ * @param mobname The mob's display name.
+ * @param class_ The mob's ID in database.
+ * @param event The name of the event which should be executed when the mob is killed.
+ * @param size The mob's size.
+ * @param ai The mob's AI.
+ * @param npc_id If spawned by NPC script, this holds the ID of the invoking NPC.
+ * @return The mob data generated by mob->spawn_dataset().
+ *
+ **/
+static struct mob_data *mob_once_spawn_sub(struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_,
+					   const char *event, unsigned int size, unsigned int ai, int npc_id)
 {
 	struct spawn_data data;
 
@@ -521,76 +551,100 @@ static struct mob_data *mob_once_spawn_sub(struct block_list *bl, int16 m, int16
 	else
 		strcpy(data.name, DEFAULT_MOB_JNAME);
 
-	if (event)
+	if (event != NULL)
 		safestrncpy(data.eventname, event, sizeof(data.eventname));
 
-	// Locate spot next to player.
-	if (bl && (x < 0 || y < 0))
+	/** Locate spot next to player. **/
+	if (bl != NULL && (x < 0 || y < 0))
 		map->search_freecell(bl, m, &x, &y, 1, 1, 0);
 
-	// if none found, pick random position on map
+	/** If none found, pick random position on map. **/
 	if (x <= 0 || x >= map->list[m].xs || y <= 0 || y >= map->list[m].ys)
 		map->search_freecell(NULL, m, &x, &y, -1, -1, 1);
 
 	data.x = x;
 	data.y = y;
 
-	if (!mob->parse_dataset(&data))
+	if (mob->parse_dataset(&data) == 0)
 		return NULL;
 
-	return mob->spawn_dataset(&data);
+	return mob->spawn_dataset(&data, npc_id);
 }
 
-/*==========================================
- * Spawn a single mob on the specified coordinates.
- *------------------------------------------*/
-static int mob_once_spawn(struct map_session_data *sd, int16 m, int16 x, int16 y, const char *mobname, int class_, int amount, const char *event, unsigned int size, unsigned int ai)
+/**
+ * Spawns a given amount of mobs.
+ *
+ * @param sd The invoking character.
+ * @param m The ID of the map where the mob should be spawned.
+ * @param x The x coordinate where the mob should be spawned.
+ * @param y The y coordinate where the mob should be spawned.
+ * @param mobname The mob's display name.
+ * @param class_ The mob's ID in database.
+ * @param amount The amount of mobs to spawn.
+ * @param event The name of the event which should be executed when the mob is killed.
+ * @param size The mob's size.
+ * @param ai The mob's AI.
+ * @return The last spawned mob's GID, or 0 if spawning failed.
+ *
+ **/
+static int mob_once_spawn(struct map_session_data *sd, int16 m, int16 x, int16 y, const char *mobname, int class_,
+			  int amount, const char *event, unsigned int size, unsigned int ai)
 {
-	struct mob_data* md = NULL;
-	int count, lv;
 	bool no_guardian_data = false;
 
-	if( ai && ai&0x200 ) {
+	if (ai > 0 && (ai & 0x200) == 0x200) {
 		no_guardian_data = true;
-		ai &=~ 0x200;
+		ai &= ~0x200;
 	}
 
 	if (m < 0 || amount <= 0)
-		return 0; // invalid input
+		return 0;
 
-	lv = (sd) ? sd->status.base_level : 255;
+	struct mob_data *md = NULL;
+
+	for (int i = 0; i < amount; i++) {
+		int mob_id = class_;
+
+		if (mob_id < 0) {
+			mob_id = mob->get_random_id(-class_ - 1, (battle_config.random_monster_checklv == 1) ? 3 : 1,
+						    (sd != NULL) ? sd->status.base_level : 255);
+		}
 
-	for (count = 0; count < amount; count++) {
-		int c = (class_ >= 0) ? class_ : mob->get_random_id(-class_ - 1, (battle_config.random_monster_checklv) ? 3 : 1, lv);
-		md = mob->once_spawn_sub((sd) ? &sd->bl : NULL, m, x, y, mobname, c, event, size, ai);
+		md = mob->once_spawn_sub((sd != NULL) ? &sd->bl : NULL, m, x, y, mobname, mob_id, event, size, ai,
+					 (sd != NULL) ? sd->npc_id : 0);
 
-		if (!md)
+		if (md == NULL)
 			continue;
 
 		if (class_ == MOBID_EMPELIUM && !no_guardian_data) {
-			struct guild_castle* gc = guild->mapindex2gc(map_id2index(m));
-			struct guild* g = (gc) ? guild->search(gc->guild_id) : NULL;
-			if( gc ) {
+			struct guild_castle *gc = guild->mapindex2gc(map_id2index(m));
+
+			if (gc != NULL) {
+				struct guild *g = guild->search(gc->guild_id);
+				
 				md->guardian_data = (struct guardian_data*)aCalloc(1, sizeof(struct guardian_data));
 				md->guardian_data->castle = gc;
 				md->guardian_data->number = MAX_GUARDIANS;
-				if( g )
+
+				if (g != NULL)
 					md->guardian_data->g = g;
-				else if( gc->guild_id ) //Guild not yet available, retry in 5.
-					timer->add(timer->gettick()+5000,mob->spawn_guardian_sub,md->bl.id,gc->guild_id);
+				else if (gc->guild_id > 0) /// Guild not yet available, retry in 5s.
+					timer->add(timer->gettick() + 5000, mob->spawn_guardian_sub, md->bl.id,
+						   gc->guild_id);
 			}
-		} // end addition [Valaris]
+		}
 
 		mob->spawn(md);
 
-		if (class_ < 0 && battle_config.dead_branch_active) {
-			//Behold Aegis's masterful decisions yet again...
-			//"I understand the "Aggressive" part, but the "Can Move" and "Can Attack" is just stupid" - Poki#3
-			sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE|MD_CANATTACK|MD_CANMOVE|MD_ANGRY, 0, 60000);
+		if (class_ < 0 && battle_config.dead_branch_active == 1) {
+			/// Behold Aegis' masterful decisions yet again...
+			/// "I understand the "Aggressive" part, but the "Can Move" and "Can Attack" is just stupid" [Poki]
+			sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE|MD_CANATTACK|MD_CANMOVE|MD_ANGRY,
+				  0, 60000);
 		}
 	}
 
-	return (md) ? md->bl.id : 0; // id of last spawned mob
+	return (md != NULL) ? md->bl.id : 0; /// ID of last spawned mob.
 }
 
 /*==========================================
@@ -649,196 +703,236 @@ static int mob_once_spawn_area(struct map_session_data *sd, int16 m, int16 x0, i
 }
 
 /**
- * Sets a guardian's guild data and liberates castle if couldn't retrieve guild data
- * @param data (int)guild_id
- * @retval Always 0
+ * Sets a guardian's guild data and liberates castle if couldn't retrieve guild data.
+ * Required because the guild data may not be available at guardian spawn time.
+ *
+ * @param tid Required parameter for timer functions. Unused inside the function.
+ * @param tick Required parameter for timer functions. Unused inside the function.
+ * @param id The guardian mob's GID.
+ * @param data The guild ID.
+ * @return 1 on success, 0 on failure.
+ *
  * @author Skotlex
+ *
  **/
 static int mob_spawn_guardian_sub(int tid, int64 tick, int id, intptr_t data)
 {
-	//Needed because the guild data may not be available at guardian spawn time.
-	struct block_list* bl = map->id2bl(id);
-	struct mob_data* md;
-	struct guild* g;
+	struct block_list *bl = map->id2bl(id);
 
-	if( bl == NULL ) //It is possible mob was already removed from map when the castle has no owner. [Skotlex]
+	if (bl == NULL || bl->type != BL_MOB) /// It is possible mob was already removed from map when the castle has no owner. [Skotlex]
 		return 0;
 
-	Assert_ret(bl->type == BL_MOB);
-	md = BL_UCAST(BL_MOB, bl);
+	struct mob_data *md = BL_UCAST(BL_MOB, bl);
 
-	nullpo_ret(md->guardian_data);
-	g = guild->search((int)data);
+	if (md->guardian_data == NULL)
+		return 0;
+
+	struct guild *g = guild->search((int)data);
 
-	if( g == NULL ) { //Liberate castle, if the guild is not found this is an error! [Skotlex]
+	if (g == NULL) { /// Liberate castle, if the guild is not found this is an error! [Skotlex]
 		ShowError("mob_spawn_guardian_sub: Couldn't load guild %d!\n", (int)data);
-		//Not sure this is the best way, but otherwise we'd be invoking this for ALL guardians spawned later on.
-		if (md->class_ == MOBID_EMPELIUM && md->guardian_data) {
+
+		/// Not sure this is the best way, but otherwise we'd be invoking this for ALL guardians spawned later on.
+		if (md->class_ == MOBID_EMPELIUM) {
 			md->guardian_data->g = NULL;
-			if( md->guardian_data->castle->guild_id ) {//Free castle up.
-				ShowNotice("Clearing ownership of castle %d (%s)\n", md->guardian_data->castle->castle_id, md->guardian_data->castle->castle_name);
+
+			if (md->guardian_data->castle->guild_id > 0) { /// Free castle up.
+				ShowNotice("mob_spawn_guardian_sub: Clearing ownership of castle %d (%s).\n",
+					   md->guardian_data->castle->castle_id,
+					   md->guardian_data->castle->castle_name);
 				guild->castledatasave(md->guardian_data->castle->castle_id, 1, 0);
 			}
 		} else {
-			if( md->guardian_data && md->guardian_data->number >= 0 && md->guardian_data->number < MAX_GUARDIANS
-				&& md->guardian_data->castle->guardian[md->guardian_data->number].visible )
-				guild->castledatasave(md->guardian_data->castle->castle_id, 10+md->guardian_data->number,0);
+			if (md->guardian_data->number >= 0 && md->guardian_data->number < MAX_GUARDIANS &&
+			    md->guardian_data->castle->guardian[md->guardian_data->number].visible == 1)
+				guild->castledatasave(md->guardian_data->castle->castle_id,
+						      10 + md->guardian_data->number, 0);
 
-			unit->free(&md->bl,CLR_OUTSIGHT); // Remove guardian.
+			unit->free(&md->bl, CLR_OUTSIGHT); /// Remove guardian.
 		}
+
 		return 0;
 	}
 
-	if( guild->checkskill(g,GD_GUARDUP) )
-		status_calc_mob(md, SCO_NONE); // Give bonuses.
+	if (guild->checkskill(g, GD_GUARDUP) > 0)
+		status_calc_mob(md, SCO_NONE); /// Give bonuses.
 
-	return 0;
+	return 1;
 }
 
-/*==========================================
- * Summoning Guardians [Valaris]
- *------------------------------------------*/
-static int mob_spawn_guardian(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index)
+/**
+ * Summons a castle guardian mob.
+ *
+ * @param mapname The name of the map where the guardian should be spawned.
+ * @param x The x coordinate where the guardian should be spawned.
+ * @param y The y coordinate where the guardian should be spawned.
+ * @param mobname The guardian's display name.
+ * @param class_ The guardian's mob ID in database.
+ * @param event The name of the event which should be executed when the guardian is killed.
+ * @param guardian The guardian's index.
+ * @param has_index If false, the guardian will be temporarily.
+ * @param npc_id If spawned by NPC script, this holds the ID of the invoking NPC.
+ * @return The spawned guardian's GID, or 0 if spawning failed.
+ *
+ * @author Valaris
+ *
+ **/
+static int mob_spawn_guardian(const char *mapname, short x, short y, const char *mobname, int class_, const char *event,
+			      int guardian, bool has_index, int npc_id)
 {
-	struct mob_data *md=NULL;
-	struct spawn_data data;
-	struct guild *g=NULL;
-	struct guild_castle *gc;
-	int16 m;
-
 	nullpo_ret(mapname);
 	nullpo_ret(mobname);
 	nullpo_ret(event);
 
-	memset(&data, 0, sizeof(struct spawn_data));
-	data.num = 1;
+	const int map_id = map->mapname2mapid(mapname);
 
-	m=map->mapname2mapid(mapname);
-
-	if(m<0)
-	{
+	if (map_id == INDEX_NOT_FOUND) {
 		ShowWarning("mob_spawn_guardian: Map [%s] not found.\n", mapname);
 		return 0;
 	}
-	data.m = m;
-	data.num = 1;
-	if(class_<=0) {
-		class_ = mob->get_random_id(-class_-1, 1, 99);
-		if (!class_) return 0;
+
+	if ((x <= 0 || y <= 0) && map->search_freecell(NULL, map_id, &x, &y, -1, -1, 1) == 0) {
+		ShowWarning("mob_spawn_guardian: Couldn't locate a spawn cell for guardian class %d (index %d) on castle map %s.\n",
+			    class_, guardian, mapname);
+		return 0;
 	}
 
-	data.class_ = class_;
+	if (class_ <= 0 && (class_ = mob->get_random_id(-class_ - 1, 1, 99)) == 0)
+		return 0;
 
-	if( !has_index ) {
+	if (!has_index) {
 		guardian = -1;
-	} else if( guardian < 0 || guardian >= MAX_GUARDIANS ) {
-		ShowError("mob_spawn_guardian: Invalid guardian index %d for guardian %d (castle map %s)\n", guardian, class_, map->list[m].name);
+	} else if (guardian < 0 || guardian >= MAX_GUARDIANS) {
+		ShowError("mob_spawn_guardian: Invalid guardian index %d for guardian %d on castle map %s.\n",
+			  guardian, class_, mapname);
 		return 0;
 	}
 
-	if((x<=0 || y<=0) && !map->search_freecell(NULL, m, &x, &y, -1,-1, 1)) {
-		ShowWarning("mob_spawn_guardian: Couldn't locate a spawn cell for guardian class %d (index %d) at castle map %s\n",class_, guardian, map->list[m].name);
-		return 0;
-	}
+	struct spawn_data data;
+
+	memset(&data, 0, sizeof(struct spawn_data));
+	data.num = 1;
+	data.m = map_id;
+	data.class_ = class_;
 	data.x = x;
 	data.y = y;
 	safestrncpy(data.name, mobname, sizeof(data.name));
 	safestrncpy(data.eventname, event, sizeof(data.eventname));
-	if (!mob->parse_dataset(&data))
+
+	if (mob->parse_dataset(&data) == 0)
 		return 0;
 
-	gc=guild->mapname2gc(map->list[m].name);
+	struct guild_castle *gc = guild->mapname2gc(mapname);
+
 	if (gc == NULL) {
-		ShowError("mob_spawn_guardian: No castle set at map %s\n", map->list[m].name);
+		ShowError("mob_spawn_guardian: No castle set on map %s.\n", mapname);
 		return 0;
 	}
-	if (!gc->guild_id)
-		ShowWarning("mob_spawn_guardian: Spawning guardian %d on a castle with no guild (castle map %s)\n", class_, map->list[m].name);
+
+	struct guild *g = NULL;
+
+	if (gc->guild_id == 0)
+		ShowWarning("mob_spawn_guardian: Spawning guardian %d on a castle map %s with no guild.\n",
+			    class_, mapname);
 	else
 		g = guild->search(gc->guild_id);
 
-	if( has_index && gc->guardian[guardian].id ) {
-		//Check if guardian already exists, refuse to spawn if so.
-		struct block_list *bl2 = map->id2bl(gc->guardian[guardian].id); // TODO: Why does this not use map->id2md?
-		struct mob_data *md2 = BL_CAST(BL_MOB, bl2);
-		if (md2 != NULL && md2->guardian_data != NULL && md2->guardian_data->number == guardian) {
-			ShowError("mob_spawn_guardian: Attempted to spawn guardian in position %d which already has a guardian (castle map %s)\n", guardian, map->list[m].name);
+	if (has_index && gc->guardian[guardian].id != 0) { /// Check if guardian already exists, refuse to spawn if so.
+		struct mob_data *md = map->id2md(gc->guardian[guardian].id);
+
+		if (md != NULL && md->guardian_data != NULL && md->guardian_data->number == guardian) {
+			ShowError("mob_spawn_guardian: Attempted to spawn guardian in position %d which already has a guardian on castle map %s.\n",
+				  guardian, mapname);
 			return 0;
 		}
 	}
 
-	md = mob->spawn_dataset(&data);
+	struct mob_data *md = mob->spawn_dataset(&data, npc_id);
+
 	md->guardian_data = (struct guardian_data*)aCalloc(1, sizeof(struct guardian_data));
 	md->guardian_data->number = guardian;
 	md->guardian_data->castle = gc;
-	if( has_index )
-	{// permanent guardian
+
+	if (has_index) { /// Permanent guardian.
 		gc->guardian[guardian].id = md->bl.id;
-	}
-	else
-	{// temporary guardian
+	} else { /// Temporary guardian.
 		int i;
+
 		ARR_FIND(0, gc->temp_guardians_max, i, gc->temp_guardians[i] == 0);
-		if( i == gc->temp_guardians_max )
-		{
+
+		if (i == gc->temp_guardians_max) {
 			++(gc->temp_guardians_max);
 			RECREATE(gc->temp_guardians, int, gc->temp_guardians_max);
 		}
+
 		gc->temp_guardians[i] = md->bl.id;
 	}
-	if( g )
+
+	if (g != NULL)
 		md->guardian_data->g = g;
-	else if( gc->guild_id )
-		timer->add(timer->gettick()+5000,mob->spawn_guardian_sub,md->bl.id,gc->guild_id);
-	mob->spawn(md);
+	else if (gc->guild_id > 0)
+		timer->add(timer->gettick() + 5000, mob->spawn_guardian_sub, md->bl.id, gc->guild_id);
 
+	mob->spawn(md);
 	return md->bl.id;
 }
 
-/*==========================================
- * Summoning BattleGround [Zephyrus]
- *------------------------------------------*/
-static int mob_spawn_bg(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id)
+/**
+ * Spawn a mob with allegiance to the given battle group.
+ *
+ * @param mapname The name of the map where the mob should be spawned.
+ * @param x The x coordinate where the mob should be spawned.
+ * @param y The y coordinate where the mob should be spawned.
+ * @param mobname The mob's display name.
+ * @param class_ The mob's mob ID in database.
+ * @param event The name of the event which should be executed when the mob is killed.
+ * @param bg_id The battle group ID.
+ * @param npc_id If spawned by NPC script, this holds the ID of the invoking NPC.
+ * @return The spawned mob's GID, or 0 if spawning failed.
+ *
+ * @author Zephyrus
+ *
+ **/
+static int mob_spawn_bg(const char *mapname, short x, short y, const char *mobname, int class_, const char *event,
+			unsigned int bg_id, int npc_id)
 {
-	struct mob_data *md = NULL;
-	struct spawn_data data;
-	int16 m;
-
 	nullpo_ret(mapname);
 	nullpo_ret(mobname);
 	nullpo_ret(event);
 
-	if( (m = map->mapname2mapid(mapname)) < 0 ) {
+	const int map_id = map->mapname2mapid(mapname);
+
+	if (map_id == INDEX_NOT_FOUND) {
 		ShowWarning("mob_spawn_bg: Map [%s] not found.\n", mapname);
 		return 0;
 	}
 
-	memset(&data, 0, sizeof(struct spawn_data));
-	data.m = m;
-	data.num = 1;
-	if( class_ <= 0 )
-	{
-		class_ = mob->get_random_id(-class_-1,1,99);
-		if( !class_ ) return 0;
+	if ((x <= 0 || y <= 0) && map->search_freecell(NULL, map_id, &x, &y, -1, -1, 1) == 0) {
+		ShowWarning("mob_spawn_bg: Couldn't locate a spawn cell for guardian class %d (bg_id %u) on map %s.\n", class_, bg_id, mapname);
+		return 0;
 	}
 
-	data.class_ = class_;
-	if( (x <= 0 || y <= 0) && !map->search_freecell(NULL, m, &x, &y, -1,-1, 1) ) {
-		ShowWarning("mob_spawn_bg: Couldn't locate a spawn cell for guardian class %d (bg_id %u) at map %s\n", class_, bg_id, map->list[m].name);
+	if (class_ <= 0 && (class_ = mob->get_random_id(-class_ - 1, 1, 99)) == 0)
 		return 0;
-	}
 
+	struct spawn_data data;
+
+	memset(&data, 0, sizeof(struct spawn_data));
+	data.num = 1;
+	data.m = map_id;
+	data.class_ = class_;
 	data.x = x;
 	data.y = y;
 	safestrncpy(data.name, mobname, sizeof(data.name));
 	safestrncpy(data.eventname, event, sizeof(data.eventname));
-	if( !mob->parse_dataset(&data) )
+
+	if (mob->parse_dataset(&data) == 0)
 		return 0;
 
-	md = mob->spawn_dataset(&data);
-	mob->spawn(md);
-	md->bg_id = bg_id; // BG Team ID
+	struct mob_data *md = mob->spawn_dataset(&data, npc_id);
 
+	mob->spawn(md);
+	md->bg_id = bg_id;
 	return md->bl.id;
 }
 
@@ -3100,18 +3194,25 @@ static int mob_countslave(struct block_list *bl)
 	return map->foreachinmap(mob->countslave_sub, bl->m, BL_MOB,bl->id);
 }
 
-/*==========================================
- * Summons amount slaves contained in the value[5] array using round-robin. [adapted by Skotlex]
- *------------------------------------------*/
+/**
+ * Summons amount slaves contained in the value[5] array using round-robin.
+ *
+ * @param md2 The mob which summons the slaves.
+ * @param value Array with slave mob IDs.
+ * @param amount The amount of slaves to spawn.
+ * @param skill_id The Id of the skill which summons the slaves.
+ * @return 1 on success, 0 on failure.
+ *
+ * @author Skotlex
+ *
+ **/
 static int mob_summonslave(struct mob_data *md2, int *value, int amount, uint16 skill_id)
 {
-	struct mob_data *md;
-	struct spawn_data data;
-	int count = 0,k=0,hp_rate=0;
-
 	nullpo_ret(md2);
 	nullpo_ret(value);
 
+	struct spawn_data data;
+
 	memset(&data, 0, sizeof(struct spawn_data));
 	data.m = md2->bl.m;
 	data.x = md2->bl.x;
@@ -3120,31 +3221,42 @@ static int mob_summonslave(struct mob_data *md2, int *value, int amount, uint16
 	data.state.size = md2->special_state.size;
 	data.state.ai = md2->special_state.ai;
 
-	if(mob->db_checkid(value[0]) == 0)
+	if (mob->db_checkid(value[0]) == 0)
 		return 0;
-	/**
-	 * Flags this monster is able to summon; saves a worth amount of memory upon deletion
-	 **/
-	md2->can_summon = 1;
 
-	while(count < 5 && mob->db_checkid(value[count])) count++;
-	if(count < 1) return 0;
-	if (amount > 0 && amount < count) { //Do not start on 0, pick some random sub subset [Skotlex]
-		k = rnd()%count;
-		amount+=k; //Increase final value by same amount to preserve total number to summon.
+	md2->can_summon = 1; /// Flags this monster is able to summon; saves a worth amount of memory upon deletion.
+
+	int count = 0;
+
+	while (count < 5 && mob->db_checkid(value[count]) != 0)
+		count++;
+
+	if (count < 1)
+		return 0;
+
+	int k = 0;
+
+	if (amount > 0 && amount < count) { /// Do not start on 0, pick some random sub subset. [Skotlex]
+		k = rnd() % count;
+		amount += k; /// Increase final value by same amount to preserve total number to summon.
 	}
 
-	if (!battle_config.monster_class_change_recover &&
-		(skill_id == NPC_TRANSFORMATION || skill_id == NPC_METAMORPHOSIS))
+	int hp_rate = 0;
+
+	if ((skill_id == NPC_TRANSFORMATION || skill_id == NPC_METAMORPHOSIS) &&
+	    battle_config.monster_class_change_recover == 0)
 		hp_rate = get_percentage(md2->status.hp, md2->status.max_hp);
 
-	for(;k<amount;k++) {
-		short x,y;
-		data.class_ = value[k%count]; //Summon slaves in round-robin fashion. [Skotlex]
+	for (; k < amount; k++) {
+		data.class_ = value[k % count]; /// Summon slaves in round-robin fashion. [Skotlex]
+
 		if (mob->db_checkid(data.class_) == 0)
 			continue;
 
-		if (map->search_freecell(&md2->bl, 0, &x, &y, MOB_SLAVEDISTANCE, MOB_SLAVEDISTANCE, 0)) {
+		short x;
+		short y;
+
+		if (map->search_freecell(&md2->bl, 0, &x, &y, MOB_SLAVEDISTANCE, MOB_SLAVEDISTANCE, 0) != 0) {
 			data.x = x;
 			data.y = y;
 		} else {
@@ -3152,49 +3264,52 @@ static int mob_summonslave(struct mob_data *md2, int *value, int amount, uint16
 			data.y = md2->bl.y;
 		}
 
-		//These two need to be loaded from the db for each slave.
 		if (battle_config.override_mob_names == 1)
 			strcpy(data.name, DEFAULT_MOB_NAME);
 		else
 			strcpy(data.name, DEFAULT_MOB_JNAME);
 
-		if (!mob->parse_dataset(&data))
+		if (mob->parse_dataset(&data) == 0)
 			continue;
 
-		md= mob->spawn_dataset(&data);
-		if(skill_id == NPC_SUMMONSLAVE){
-			md->master_id=md2->bl.id;
+		struct mob_data *md = mob->spawn_dataset(&data, 0);
+
+		if (skill_id == NPC_SUMMONSLAVE) {
+			md->master_id = md2->bl.id;
 			md->special_state.ai = md2->special_state.ai;
 		}
+
 		mob->spawn(md);
 
-		if (hp_rate) //Scale HP
-			md->status.hp = md->status.max_hp*hp_rate/100;
+		if (hp_rate > 0) /// Scale HP.
+			md->status.hp = md->status.max_hp * hp_rate / 100;
 
-		//Inherit the aggressive mode of the master.
-		if (battle_config.slaves_inherit_mode && md->master_id) {
+		/** Inherit the aggressive mode of the master. **/
+		if (battle_config.slaves_inherit_mode > 0 && md->master_id > 0) {
 			switch (battle_config.slaves_inherit_mode) {
-			case 1: //Always aggressive
-				if (!(md->status.mode&MD_AGGRESSIVE))
-					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100,1,0, MD_AGGRESSIVE, 0, 0);
+			case 1: /// Always aggressive.
+				if ((md->status.mode & MD_AGGRESSIVE) == 0)
+					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
+
 				break;
-			case 2: //Always passive
-				if (md->status.mode&MD_AGGRESSIVE)
-					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100,1,0, 0, MD_AGGRESSIVE, 0);
+			case 2: /// Always passive.
+				if ((md->status.mode & MD_AGGRESSIVE) == MD_AGGRESSIVE)
+					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
+
 				break;
-			default: //Copy master.
-				if (md2->status.mode&MD_AGGRESSIVE)
-					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100,1,0, MD_AGGRESSIVE, 0, 0);
+			default: /// Copy master.
+				if ((md2->status.mode & MD_AGGRESSIVE) == MD_AGGRESSIVE)
+					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
 				else
-					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100,1,0, 0, MD_AGGRESSIVE, 0);
+					sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
 				break;
 			}
 		}
 
-		clif->skill_nodamage(&md->bl,&md->bl,skill_id,amount,1);
+		clif->skill_nodamage(&md->bl, &md->bl, skill_id, amount, 1);
 	}
 
-	return 0;
+	return 1;
 }
 
 /*==========================================
@@ -3588,211 +3703,238 @@ static int mob_is_clone(int class_)
 	return class_;
 }
 
-//Flag values:
-//&1: Set special AI (fight mobs, not players)
-//If mode is not passed, a default aggressive mode is used.
-//If master_id is passed, clone is attached to him.
-//Returns: ID of newly crafted copy.
-static int mob_clone_spawn(struct map_session_data *sd, int16 m, int16 x, int16 y, const char *event, int master_id, uint32 mode, int flag, unsigned int duration)
+/**
+ * Spawns a mob which is a clone of another character.
+ *
+ * @param sd The character which should be cloned.
+ * @param m The ID of the map where the clone should be spawned.
+ * @param x The x coordinate where the clone should be spawned.
+ * @param y The y coordinate where the clone should be spawned.
+ * @param event The name of the event which should be executed when the clone is killed.
+ * @param master_id If passed, the clone will be attached to this account ID.
+ * @param mode The clone's mob mode(s). (Defaults to MD_CANMOVE|MD_AGGRESSIVE|MD_ASSIST|MD_CANATTACK.)
+ * @param flag 0 - target characters; 1 - target mobs.
+ * @param duration How long the clone will live before it is auto-removed. (ms)
+ * @return The spawned clone's GID, or 0 if spawning failed.
+ *
+ **/
+static int mob_clone_spawn(struct map_session_data *sd, int16 m, int16 x, int16 y, const char *event, int master_id,
+			   uint32 mode, int flag, unsigned int duration)
 {
-	int class_;
-	int i,j,h,inf, fd;
-	struct mob_data *md;
-	struct mob_skill *ms;
-	struct mob_db* db;
-	struct status_data *mstatus;
-
 	nullpo_ret(sd);
 
-	if(pc_isdead(sd) && master_id && flag&1)
+	if (pc_isdead(sd) && master_id != 0 && flag == 1)
 		return 0;
 
-	ARR_FIND( MOB_CLONE_START, MOB_CLONE_END, class_, mob->db_data[class_] == NULL );
-	if(class_ < 0 || class_ >= MOB_CLONE_END)
+	int class_;
+
+	ARR_FIND(MOB_CLONE_START, MOB_CLONE_END, class_, mob->db_data[class_] == NULL);
+
+	if (class_ < 0 || class_ >= MOB_CLONE_END)
 		return 0;
 
-	db = mob->db_data[class_]=(struct mob_db*)aCalloc(1, sizeof(struct mob_db));
-	mstatus = &db->status;
-	strcpy(db->sprite,sd->status.name);
-	strcpy(db->name,sd->status.name);
-	strcpy(db->jname,sd->status.name);
-	db->lv=status->get_lv(&sd->bl);
+	mob->db_data[class_] = (struct mob_db*)aCalloc(1, sizeof(struct mob_db));
+
+	struct mob_db *db = mob->db_data[class_];
+	struct status_data *mstatus = &db->status;
+
+	strcpy(db->sprite, sd->status.name);
+	strcpy(db->name, sd->status.name);
+	strcpy(db->jname, sd->status.name);
+	db->lv = status->get_lv(&sd->bl);
 	memcpy(mstatus, &sd->base_status, sizeof(struct status_data));
-	mstatus->rhw.atk2= mstatus->dex + mstatus->rhw.atk + mstatus->rhw.atk2; //Max ATK
-	mstatus->rhw.atk = mstatus->dex; //Min ATK
-	if (mstatus->lhw.atk) {
-		mstatus->lhw.atk2= mstatus->dex + mstatus->lhw.atk + mstatus->lhw.atk2; //Max ATK
-		mstatus->lhw.atk = mstatus->dex; //Min ATK
+	mstatus->rhw.atk2 = mstatus->dex + mstatus->rhw.atk + mstatus->rhw.atk2; /// Max ATK.
+	mstatus->rhw.atk = mstatus->dex; /// Min ATK.
+
+	if (mstatus->lhw.atk > 0) {
+		mstatus->lhw.atk2 = mstatus->dex + mstatus->lhw.atk + mstatus->lhw.atk2; /// Max ATK.
+		mstatus->lhw.atk = mstatus->dex; /// Min ATK.
 	}
-	if (mode != MD_NONE) //User provided mode.
+
+	if (mode != MD_NONE) /// User provided mode.
 		mstatus->mode = mode;
-	else if (flag&1) //Friendly Character, remove looting.
+	else if (flag == 1) /// Friendly Character, remove looting.
 		mstatus->mode &= ~MD_LOOTER;
+
 	mstatus->hp = mstatus->max_hp;
 	mstatus->sp = mstatus->max_sp;
 	memcpy(&db->vd, &sd->vd, sizeof(struct view_data));
-	db->base_exp=1;
-	db->job_exp=1;
-	db->range2=AREA_SIZE; //Let them have the same view-range as players.
-	db->range3=AREA_SIZE; //Min chase of a screen.
-	db->option=sd->sc.option;
+	db->base_exp = 1;
+	db->job_exp = 1;
+	db->range2 = AREA_SIZE; /// Let them have the same view-range as players.
+	db->range3 = AREA_SIZE; /// Min chase of a screen.
+	db->option = sd->sc.option;
 
-	//Skill copy [Skotlex]
-	ms = &db->skill[0];
+	const int fd = sd->fd;
 
-	/**
-	 * We temporarily disable sd's fd so it doesn't receive the messages from skill_check_condition_castbegin
-	 **/
-	fd = sd->fd;
-	sd->fd = 0;
-
-	//Go Backwards to give better priority to advanced skills.
-	for (i=0,j = MAX_SKILL_TREE-1;j>=0 && i< MAX_MOBSKILL ;j--) {
-		int idx = pc->skill_tree[pc->class2idx(sd->status.class)][j].idx;
-		int skill_id = pc->skill_tree[pc->class2idx(sd->status.class)][j].id;
-		if (!skill_id || sd->status.skill[idx].lv < 1 ||
-			(skill->dbs->db[idx].inf2&(INF2_WEDDING_SKILL|INF2_GUILD_SKILL))
-		)
+	sd->fd = 0; /// Temporarily disable sd's fd so it doesn't receive the messages from skill_check_condition_castbegin.
+
+	struct mob_skill *mob_skills = &db->skill[0];
+
+	/// Go Backwards to give better priority to advanced skills.
+	for (int i = 0, j = MAX_SKILL_TREE - 1; j >= 0 && i < MAX_MOBSKILL; j--) {
+		const int idx = pc->skill_tree[pc->class2idx(sd->status.class)][j].idx;
+		const int skill_id = pc->skill_tree[pc->class2idx(sd->status.class)][j].id;
+
+		if (skill_id == 0 || sd->status.skill[idx].lv < 1 ||
+		    (skill->dbs->db[idx].inf2 & (INF2_WEDDING_SKILL | INF2_GUILD_SKILL)) > 0)
 			continue;
-		for(h = 0; h < map->list[sd->bl.m].zone->disabled_skills_count; h++) {
-			if( skill_id == map->list[sd->bl.m].zone->disabled_skills[h]->nameid && map->list[sd->bl.m].zone->disabled_skills[h]->subtype == MZS_CLONE ) {
+
+		int h;
+
+		for (h = 0; h < map->list[sd->bl.m].zone->disabled_skills_count; h++) {
+			if (skill_id == map->list[sd->bl.m].zone->disabled_skills[h]->nameid &&
+			    map->list[sd->bl.m].zone->disabled_skills[h]->subtype == MZS_CLONE)
 				break;
-			}
 		}
-		if( h < map->list[sd->bl.m].zone->disabled_skills_count )
+
+		if (h < map->list[sd->bl.m].zone->disabled_skills_count)
 			continue;
-		//Normal aggressive mob, disable skills that cannot help them fight
-		//against players (those with flags UF_NOMOB and UF_NOPC are specific
-		//to always aid players!) [Skotlex]
-		if (!(flag&1) &&
-			skill->get_unit_id(skill_id, 0) &&
-			skill->get_unit_flag(skill_id)&(UF_NOMOB|UF_NOPC))
+
+		/// Normal aggressive mob. Disable skills that cannot help fighting against players. (Those with flags UF_NOMOB and UF_NOPC are specific to always aid players!) [Skotlex]
+		if (flag == 0 && skill->get_unit_id(skill_id, 0) != 0 &&
+		    (skill->get_unit_flag(skill_id) & (UF_NOMOB | UF_NOPC)) > 0)
 			continue;
-		/**
-		 * The clone should be able to cast the skill (e.g. have the required weapon) bugreport:5299)
-		 **/
-		if( !skill->check_condition_castbegin(sd,skill_id,sd->status.skill[idx].lv) )
+
+		/// The clone should be able to cast the skill. (E.g. have the required weapon.) [bugreport:5299]
+		if (skill->check_condition_castbegin(sd, skill_id, sd->status.skill[idx].lv) == 0)
 			continue;
 
-		memset (&ms[i], 0, sizeof(struct mob_skill));
-		ms[i].skill_id = skill_id;
-		ms[i].skill_lv = sd->status.skill[idx].lv;
-		ms[i].state = MSS_ANY;
-		ms[i].permillage = 500*battle_config.mob_skill_rate/100; //Default chance of all skills: 5%
-		ms[i].emotion = -1;
-		ms[i].cancel = 0;
-		ms[i].casttime = skill->cast_fix(&sd->bl,skill_id, ms[i].skill_lv);
-		ms[i].delay = 5000+skill->delay_fix(&sd->bl,skill_id, ms[i].skill_lv);
-
-		inf = skill->dbs->db[idx].inf;
-		if (inf&INF_ATTACK_SKILL) {
-			ms[i].target = MST_TARGET;
-			ms[i].cond1 = MSC_ALWAYS;
-			if (skill->get_range(skill_id, ms[i].skill_lv)  > 3)
-				ms[i].state = MSS_ANYTARGET;
+		memset(&mob_skills[i], 0, sizeof(struct mob_skill));
+		mob_skills[i].skill_id = skill_id;
+		mob_skills[i].skill_lv = sd->status.skill[idx].lv;
+		mob_skills[i].state = MSS_ANY;
+		mob_skills[i].permillage = 500 * battle_config.mob_skill_rate / 100; /// Default chance of all skills: 5%
+		mob_skills[i].emotion = -1;
+		mob_skills[i].cancel = 0;
+		mob_skills[i].casttime = skill->cast_fix(&sd->bl, skill_id, mob_skills[i].skill_lv);
+		mob_skills[i].delay = 5000 + skill->delay_fix(&sd->bl, skill_id, mob_skills[i].skill_lv);
+
+		const int inf = skill->dbs->db[idx].inf;
+
+		if ((inf & INF_ATTACK_SKILL) == INF_ATTACK_SKILL) {
+			mob_skills[i].target = MST_TARGET;
+			mob_skills[i].cond1 = MSC_ALWAYS;
+
+			if (skill->get_range(skill_id, mob_skills[i].skill_lv) > 3)
+				mob_skills[i].state = MSS_ANYTARGET;
 			else
-				ms[i].state = MSS_BERSERK;
-		} else if(inf&INF_GROUND_SKILL) {
-			if (skill->get_inf2(skill_id)&INF2_TRAP) { //Traps!
-				ms[i].state = MSS_IDLE;
-				ms[i].target = MST_AROUND2;
-				ms[i].delay = 60000;
-			} else if (skill->get_unit_target(skill_id) == BCT_ENEMY) { //Target Enemy
-				ms[i].state = MSS_ANYTARGET;
-				ms[i].target = MST_TARGET;
-				ms[i].cond1 = MSC_ALWAYS;
-			} else { //Target allies
-				ms[i].target = MST_FRIEND;
-				ms[i].cond1 = MSC_FRIENDHPLTMAXRATE;
-				ms[i].cond2 = 95;
+				mob_skills[i].state = MSS_BERSERK;
+		} else if ((inf & INF_GROUND_SKILL) == INF_GROUND_SKILL) {
+			if ((skill->get_inf2(skill_id) & INF2_TRAP) == INF2_TRAP) { /// Traps!
+				mob_skills[i].state = MSS_IDLE;
+				mob_skills[i].target = MST_AROUND2;
+				mob_skills[i].delay = 60000;
+			} else if (skill->get_unit_target(skill_id) == BCT_ENEMY) { /// Target Enemy.
+				mob_skills[i].state = MSS_ANYTARGET;
+				mob_skills[i].target = MST_TARGET;
+				mob_skills[i].cond1 = MSC_ALWAYS;
+			} else { /// Target allies.
+				mob_skills[i].target = MST_FRIEND;
+				mob_skills[i].cond1 = MSC_FRIENDHPLTMAXRATE;
+				mob_skills[i].cond2 = 95;
 			}
-		} else if (inf&INF_SELF_SKILL) {
-			if (skill->get_inf2(skill_id)&INF2_NO_TARGET_SELF) { //auto-select target skill.
-				ms[i].target = MST_TARGET;
-				ms[i].cond1 = MSC_ALWAYS;
-				if (skill->get_range(skill_id, ms[i].skill_lv)  > 3) {
-					ms[i].state = MSS_ANYTARGET;
-				} else {
-					ms[i].state = MSS_BERSERK;
-				}
-			} else { //Self skill
-				ms[i].target = MST_SELF;
-				ms[i].cond1 = MSC_MYHPLTMAXRATE;
-				ms[i].cond2 = 90;
-				ms[i].permillage = 2000;
-				//Delay: Remove the stock 5 secs and add half of the support time.
-				ms[i].delay += -5000 +(skill->get_time(skill_id, ms[i].skill_lv) + skill->get_time2(skill_id, ms[i].skill_lv))/2;
-				if (ms[i].delay < 5000)
-					ms[i].delay = 5000; //With a minimum of 5 secs.
+		} else if ((inf & INF_SELF_SKILL) == INF_SELF_SKILL) {
+			if ((skill->get_inf2(skill_id) & INF2_NO_TARGET_SELF) == INF2_NO_TARGET_SELF) { /// Auto-select target skill.
+				mob_skills[i].target = MST_TARGET;
+				mob_skills[i].cond1 = MSC_ALWAYS;
+
+				if (skill->get_range(skill_id, mob_skills[i].skill_lv) > 3)
+					mob_skills[i].state = MSS_ANYTARGET;
+				else
+					mob_skills[i].state = MSS_BERSERK;
+			} else { /// Self skill.
+				mob_skills[i].target = MST_SELF;
+				mob_skills[i].cond1 = MSC_MYHPLTMAXRATE;
+				mob_skills[i].cond2 = 90;
+				mob_skills[i].permillage = 2000;
+
+				const int time1 = skill->get_time(skill_id, mob_skills[i].skill_lv);
+				const int time2 = skill->get_time2(skill_id, mob_skills[i].skill_lv);
+
+				/** Delay: Remove the stock 5 secs and add half of the support time. **/
+				mob_skills[i].delay += -5000 + (time1 + time2) / 2;
+
+				if (mob_skills[i].delay < 5000)
+					mob_skills[i].delay = 5000; /// With a minimum of 5 seconds.
 			}
-		} else if (inf&INF_SUPPORT_SKILL) {
-			ms[i].target = MST_FRIEND;
-			ms[i].cond1 = MSC_FRIENDHPLTMAXRATE;
-			ms[i].cond2 = 90;
+		} else if ((inf & INF_SUPPORT_SKILL) == INF_SUPPORT_SKILL) {
+			mob_skills[i].target = MST_FRIEND;
+			mob_skills[i].cond1 = MSC_FRIENDHPLTMAXRATE;
+			mob_skills[i].cond2 = 90;
+
 			if (skill_id == AL_HEAL)
-				ms[i].permillage = 5000; //Higher skill rate usage for heal.
+				mob_skills[i].permillage = 5000; /// Higher skill rate usage for heal.
 			else if (skill_id == ALL_RESURRECTION)
-				ms[i].cond2 = 1;
-			//Delay: Remove the stock 5 secs and add half of the support time.
-			ms[i].delay += -5000 +(skill->get_time(skill_id, ms[i].skill_lv) + skill->get_time2(skill_id, ms[i].skill_lv))/2;
-			if (ms[i].delay < 2000)
-				ms[i].delay = 2000; //With a minimum of 2 secs.
-
-			if (i+1 < MAX_MOBSKILL) { //duplicate this so it also triggers on self.
-				memcpy(&ms[i+1], &ms[i], sizeof(struct mob_skill));
+				mob_skills[i].cond2 = 1;
+
+			const int time1 = skill->get_time(skill_id, mob_skills[i].skill_lv);
+			const int time2 = skill->get_time2(skill_id, mob_skills[i].skill_lv);
+
+			/** Delay: Remove the stock 5 secs and add half of the support time. **/
+			mob_skills[i].delay += -5000 + (time1 + time2) / 2;
+
+			if (mob_skills[i].delay < 2000)
+				mob_skills[i].delay = 2000; /// With a minimum of 2 seconds.
+
+			if (i + 1 < MAX_MOBSKILL) { /// Duplicate this so it also triggers on self.
+				memcpy(&mob_skills[i + 1], &mob_skills[i], sizeof(struct mob_skill));
 				db->maxskill = ++i;
-				ms[i].target = MST_SELF;
-				ms[i].cond1 = MSC_MYHPLTMAXRATE;
+				mob_skills[i].target = MST_SELF;
+				mob_skills[i].cond1 = MSC_MYHPLTMAXRATE;
 			}
 		} else {
-			switch (skill_id) { //Certain Special skills that are passive, and thus, never triggered.
-				case MO_TRIPLEATTACK:
-				case TF_DOUBLE:
-				case GS_CHAINACTION:
-					ms[i].state = MSS_BERSERK;
-					ms[i].target = MST_TARGET;
-					ms[i].cond1 = MSC_ALWAYS;
-					ms[i].permillage = skill_id==MO_TRIPLEATTACK?(3000-ms[i].skill_lv*100):(ms[i].skill_lv*500);
-					ms[i].delay -= 5000; //Remove the added delay as these could trigger on "all hits".
-					break;
-				default: //Untreated Skill
-					continue;
+			switch (skill_id) { /// Certain special skills that are passive, and thus, never triggered.
+			case MO_TRIPLEATTACK:
+				FALLTHROUGH
+			case TF_DOUBLE:
+				FALLTHROUGH
+			case GS_CHAINACTION:
+				mob_skills[i].state = MSS_BERSERK;
+				mob_skills[i].target = MST_TARGET;
+				mob_skills[i].cond1 = MSC_ALWAYS;
+
+				if (skill_id == MO_TRIPLEATTACK)
+					mob_skills[i].permillage = 3000 - mob_skills[i].skill_lv * 100;
+				else
+					mob_skills[i].permillage = mob_skills[i].skill_lv * 500;
+
+				mob_skills[i].delay -= 5000; /// Remove the added delay as these could trigger on "all hits".
+				break;
+			default: /// Untreated skill.
+				continue;
 			}
 		}
-		if (battle_config.mob_skill_rate!= 100)
-			ms[i].permillage = ms[i].permillage*battle_config.mob_skill_rate/100;
-		if (battle_config.mob_skill_delay != 100)
-			ms[i].delay = ms[i].delay*battle_config.mob_skill_delay/100;
 
+		mob_skills[i].permillage *= battle_config.mob_skill_rate / 100;
+		mob_skills[i].delay *= battle_config.mob_skill_delay / 100;
 		db->maxskill = ++i;
 	}
 
-	/**
-	 * We grant the session it's fd value back.
-	 **/
-	sd->fd = fd;
+	sd->fd = fd; /// We grant the session it's fd value back.
+
+	/// Finally spawn it.
+	struct mob_data *md = mob->once_spawn_sub(&sd->bl, m, x, y, DEFAULT_MOB_NAME, class_, event, SZ_SMALL, AI_NONE, 0);
 
-	//Finally, spawn it.
-	md = mob->once_spawn_sub(&sd->bl, m, x, y, DEFAULT_MOB_NAME, class_, event, SZ_SMALL, AI_NONE);
-	if (!md) return 0; //Failed?
+	if (md == NULL)
+		return 0; /// Failed?
 
 	md->special_state.clone = 1;
 
-	if (master_id || flag || duration) { //Further manipulate crafted char.
-		if (flag&1) //Friendly Character
-			md->special_state.ai = AI_ATTACK;
-		if (master_id) //Attach to Master
-			md->master_id = master_id;
-		if (duration) //Auto Delete after a while.
-		{
-			if( md->deletetimer != INVALID_TIMER )
-				timer->delete(md->deletetimer, mob->timer_delete);
-			md->deletetimer = timer->add(timer->gettick() + duration, mob->timer_delete, md->bl.id, 0);
-		}
+	if (flag == 1) /// Friendly character.
+		md->special_state.ai = AI_ATTACK;
+
+	if (master_id != 0) /// Attach to master.
+		md->master_id = master_id;
+
+	if (duration > 0) { /// Auto delete after a while.
+		if (md->deletetimer != INVALID_TIMER)
+			timer->delete(md->deletetimer, mob->timer_delete);
+
+		md->deletetimer = timer->add(timer->gettick() + duration, mob->timer_delete, md->bl.id, 0);
 	}
 
 	mob->spawn(md);
-
 	return md->bl.id;
 }
 
diff --git a/src/map/mob.h b/src/map/mob.h
index 8fd16f191..8839809f2 100644
--- a/src/map/mob.h
+++ b/src/map/mob.h
@@ -255,6 +255,7 @@ struct mob_data {
 	int areanpc_id; //Required in OnTouchNPC (to avoid multiple area touchs)
 	unsigned int bg_id; // BattleGround System
 	int clan_id; // Clan System
+	int npc_id; // NPC ID if spawned with monster/areamonster/guardian/bg_monster/atcommand("@monster xy") (Used to kill mob on NPC unload.)
 
 	int64 next_walktime, last_thinktime, last_linktime, last_pcneartime, dmgtick;
 	short move_fail_count;
@@ -507,14 +508,14 @@ struct mob_interface {
 	int (*db_checkid) (const int id);
 	struct view_data* (*get_viewdata) (int class_);
 	int (*parse_dataset) (struct spawn_data *data);
-	struct mob_data* (*spawn_dataset) (struct spawn_data *data);
+	struct mob_data* (*spawn_dataset) (struct spawn_data *data, int npc_id);
 	int (*get_random_id) (int type, int flag, int lv);
 	bool (*ksprotected) (struct block_list *src, struct block_list *target);
-	struct mob_data* (*once_spawn_sub) (struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai);
+	struct mob_data* (*once_spawn_sub) (struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai, int npc_id);
 	int (*once_spawn) (struct map_session_data *sd, int16 m, int16 x, int16 y, const char *mobname, int class_, int amount, const char *event, unsigned int size, unsigned int ai);
 	int (*once_spawn_area) (struct map_session_data *sd, int16 m, int16 x0, int16 y0, int16 x1, int16 y1, const char *mobname, int class_, int amount, const char *event, unsigned int size, unsigned int ai);
-	int (*spawn_guardian) (const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index);
-	int (*spawn_bg) (const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id);
+	int (*spawn_guardian) (const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index, int npc_id);
+	int (*spawn_bg) (const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id, int npc_id);
 	int (*can_reach) (struct mob_data *md, struct block_list *bl, int range, int state);
 	int (*linksearch) (struct block_list *bl, va_list ap);
 	int (*delayspawn) (int tid, int64 tick, int id, intptr_t data);
diff --git a/src/map/npc.c b/src/map/npc.c
index 657fb987e..d369aca82 100644
--- a/src/map/npc.c
+++ b/src/map/npc.c
@@ -2935,126 +2935,193 @@ static int npc_unload_ev_label(union DBKey key, struct DBData *data, va_list ap)
 	return 0;
 }
 
-//Chk if npc matches src_id, then unload.
-//Sub-function used to find duplicates.
+/**
+ * Unloads a NPC if it's a duplicate of the passed one.
+ *
+ * @param nd The NPC to check.
+ * @param args List of arguments.
+ * @return Always 0.
+ *
+ **/
 static int npc_unload_dup_sub(struct npc_data *nd, va_list args)
 {
-	int src_id;
-
 	nullpo_ret(nd);
-	src_id = va_arg(args, int);
+
+	const int src_id = va_arg(args, int);
+	const int unload_mobs = va_arg(args, int);
+
 	if (nd->src_id == src_id)
-		npc->unload(nd, true);
+		npc->unload(nd, true, (unload_mobs == 1));
+
 	return 0;
 }
 
-//Removes all npcs that are duplicates of the passed one. [Skotlex]
-static void npc_unload_duplicates(struct npc_data *nd)
+/**
+ * Unloads all NPCs which are duplicates of the passed one.
+ *
+ * @param nd The source NPC.
+ * @param unload_mobs If true, mobs spawned by duplicates will be removed.
+ *
+ * @author Skotlex
+ *
+ **/
+static void npc_unload_duplicates(struct npc_data *nd, bool unload_mobs)
 {
 	nullpo_retv(nd);
-	map->foreachnpc(npc->unload_dup_sub,nd->bl.id);
+
+	map->foreachnpc(npc->unload_dup_sub, nd->bl.id, unload_mobs);
+}
+
+/**
+ * Removes a mob, which was spawned by a NPC (monster/areamonster/guardian/bg_monster/atcommand("@monster xy")).
+ *
+ * @param md The mob to remove.
+ * @param args List of arguments.
+ * @return 1 on success, 0 on failure.
+ *
+ * @author Kenpachi
+ *
+ **/
+static int npc_unload_mob(struct mob_data *md, va_list args)
+{
+	nullpo_ret(md);
+
+	const int npc_id = va_arg(args, int);
+
+	if (md->npc_id == npc_id) {
+		md->state.npc_killmonster = 1;
+		status_kill(&md->bl);
+		return 1;
+	}
+
+	return 0;
 }
 
-//Removes an npc from map and db.
-//Single is to free name (for duplicates).
-static int npc_unload(struct npc_data *nd, bool single)
+/**
+ * Removes a NPC from map and database.
+ *
+ * @param nd The NPC which should be removed.
+ * @param single If true, names are freed. (For duplicates.)
+ * @param unload_mobs If true, mobs spawned by the NPC will be removed.
+ * @return Always 0.
+ *
+ **/
+static int npc_unload(struct npc_data *nd, bool single, bool unload_mobs)
 {
 	nullpo_ret(nd);
 
-	if( nd->ud && nd->ud != &npc->base_ud ) {
+	if (nd->ud != NULL && nd->ud != &npc->base_ud)
 		skill->clear_unitgroup(&nd->bl);
-	}
 
 	npc->remove_map(nd);
 	map->deliddb(&nd->bl);
-	if( single )
+
+	if (single)
 		strdb_remove(npc->name_db, nd->exname);
 
-	if (nd->chat_id) // remove npc chatroom object and kick users
+	if (nd->chat_id != 0) /// Remove NPC chatroom object and kick users.
 		chat->delete_npc_chat(nd);
 
-	npc_chat->finalize(nd); // deallocate npc PCRE data structures
+	npc_chat->finalize(nd); /// Deallocate NPC PCRE data structures.
 
 	if (single && nd->path != NULL) {
 		npc->releasepathreference(nd->path);
 		nd->path = NULL;
 	}
 
-	if (single && nd->bl.m != -1)
+	if (single && nd->bl.m != INDEX_NOT_FOUND)
 		map->remove_questinfo(nd->bl.m, nd);
+
 	npc->questinfo_clear(nd);
 
-	if (nd->src_id == 0 && ( nd->subtype == SHOP || nd->subtype == CASHSHOP)) {
-		//src check for duplicate shops [Orcao]
-		aFree(nd->u.shop.shop_item);
+	if (nd->src_id == 0 && (nd->subtype == SHOP || nd->subtype == CASHSHOP)) {
+		aFree(nd->u.shop.shop_item); /// src check for duplicate shops. [Orcao]
 	} else if (nd->subtype == SCRIPT) {
-		struct s_mapiterator *iter;
-		struct map_session_data *sd = NULL;
+		char evname[EVENT_NAME_LENGTH];
+		
+		snprintf(evname, ARRAYLENGTH(evname), "%s::OnNPCUnload", nd->exname);
+
+		struct event_data *ev = strdb_get(npc->ev_db, evname);
+		
+		if (ev != NULL)
+			script->run_npc(nd->u.scr.script, ev->pos, 0, nd->bl.id); /// Run OnNPCUnload.
 
-		if( single ) {
-			npc->ev_db->foreach(npc->ev_db,npc->unload_ev,nd->exname); //Clean up all events related
-			npc->ev_label_db->foreach(npc->ev_label_db,npc->unload_ev_label,nd);
+		if (single) {
+			npc->ev_db->foreach(npc->ev_db, npc->unload_ev, nd->exname); /// Clean up all related events.
+			npc->ev_label_db->foreach(npc->ev_label_db, npc->unload_ev_label, nd);
 		}
 
-		iter = mapit_geteachpc();
-		for (sd = BL_UCAST(BL_PC, mapit->first(iter)); mapit->exists(iter); sd = BL_UCAST(BL_PC, mapit->next(iter))) {
-			if (sd->npc_timer_id != INVALID_TIMER ) {
+		struct s_mapiterator *iter = mapit_geteachpc();
+		struct map_session_data *sd = BL_UCAST(BL_PC, mapit->first(iter));
+
+		for (; mapit->exists(iter); sd = BL_UCAST(BL_PC, mapit->next(iter))) {
+			if (sd->npc_timer_id != INVALID_TIMER) {
 				const struct TimerData *td = timer->get(sd->npc_timer_id);
 
-				if( td && td->id != nd->bl.id )
+				if (td != NULL && td->id != nd->bl.id)
 					continue;
 
-				if( td && td->data )
+				if (td != NULL && td->data != 0)
 					ers_free(npc->timer_event_ers, (void*)td->data);
+
 				timer->delete(sd->npc_timer_id, npc->timerevent);
 				sd->npc_timer_id = INVALID_TIMER;
 			}
 		}
+
 		mapit->free(iter);
 
 		if (nd->u.scr.timerid != INVALID_TIMER) {
-			const struct TimerData *td;
-			td = timer->get(nd->u.scr.timerid);
-			if (td && td->data)
+			const struct TimerData *td = timer->get(nd->u.scr.timerid);
+
+			if (td != NULL && td->data != 0)
 				ers_free(npc->timer_event_ers, (void*)td->data);
+
 			timer->delete(nd->u.scr.timerid, npc->timerevent);
 		}
-		if (nd->u.scr.timer_event)
+
+		if (nd->u.scr.timer_event != NULL)
 			aFree(nd->u.scr.timer_event);
+
 		if (nd->src_id == 0) {
-			if(nd->u.scr.script) {
+			if (nd->u.scr.script != NULL) {
 				script->free_code(nd->u.scr.script);
 				nd->u.scr.script = NULL;
 			}
-			if (nd->u.scr.label_list) {
+
+			if (nd->u.scr.label_list != NULL) {
 				aFree(nd->u.scr.label_list);
 				nd->u.scr.label_list = NULL;
 				nd->u.scr.label_list_num = 0;
 			}
-			if(nd->u.scr.shop) {
-				if(nd->u.scr.shop->item) {
+
+			if (nd->u.scr.shop != NULL) {
+				if (nd->u.scr.shop->item != NULL) {
 					for (int i = 0; i < nd->u.scr.shop->items; i ++) {
-						if (nd->u.scr.shop->item[i].currency)
+						if (nd->u.scr.shop->item[i].currency != NULL)
 							aFree(nd->u.scr.shop->item[i].currency);
 					}
 					aFree(nd->u.scr.shop->item);
 				}
+
 				aFree(nd->u.scr.shop);
 			}
 		}
-		if( nd->u.scr.guild_id )
+
+		if (nd->u.scr.guild_id > 0)
 			guild->flag_remove(nd);
 	}
 
-	if( nd->ud && nd->ud != &npc->base_ud ) {
+	if (nd->ud != NULL && nd->ud != &npc->base_ud) {
 		aFree(nd->ud);
 		nd->ud = NULL;
 	}
 
-	HPM->data_store_destroy(&nd->hdata);
+	if (unload_mobs)
+		map->foreachmob(npc->unload_mob, nd->bl.id);
 
+	HPM->data_store_destroy(&nd->hdata);
 	aFree(nd);
-
 	return 0;
 }
 
@@ -4431,18 +4498,23 @@ static const char *npc_parse_function(const char *w1, const char *w2, const char
 	return end;
 }
 
-/*==========================================
- * Parse Mob 1 - Parse mob list into each map
- * Parse Mob 2 - Actually Spawns Mob
- * [Wizputer]
- *------------------------------------------*/
+/**
+ * Spawns a mob by using the passed spawn data. (Permanent mob spawns.)
+ * npc_parse_mob() - Parses mob list into each map.
+ * npc_parse_mob2() - Actually spawns mob.
+ *
+ * @param mobspawn The mobs spawn data.
+ *
+ * @author Wizputer
+ *
+ **/
 static void npc_parse_mob2(struct spawn_data *mobspawn)
 {
-	int i;
-
 	nullpo_retv(mobspawn);
-	for( i = mobspawn->active; i < mobspawn->num; ++i ) {
-		struct mob_data* md = mob->spawn_dataset(mobspawn);
+
+	for (int i = mobspawn->active; i < mobspawn->num; ++i) {
+		struct mob_data *md = mob->spawn_dataset(mobspawn, 0);
+
 		md->spawn = mobspawn;
 		md->spawn->active++;
 		mob->spawn(md);
@@ -5499,129 +5571,143 @@ static void npc_process_files(int npc_min)
 		npc->npc_id - npc_min, npc->npc_warp, npc->npc_shop, npc->npc_script, npc->npc_mob, npc->npc_cache_mob, npc->npc_delay_mob);
 }
 
-//Clear then reload npcs files
+/**
+ * Clears and then reloads all NPC files.
+ *
+ * @return Always 0.
+ *
+ **/
 static int npc_reload(void)
 {
-	int npc_new_min = npc->npc_id;
-	struct s_mapiterator* iter;
-	struct block_list* bl;
-
-	if (map->retval == EXIT_FAILURE)
-		map->retval = EXIT_SUCCESS; // Clear return status in case something failed before.
-
-	/* clear guild flag cache */
-	guild->flags_clear();
+	if (map->retval == EXIT_FAILURE) /// Clear return status in case something failed before.
+		map->retval = EXIT_SUCCESS;
 
+	guild->flags_clear(); /// Clear guild flag cache.
 	npc->path_db->clear(npc->path_db, npc->path_db_clear_sub);
-
 	db_clear(npc->name_db);
 	db_clear(npc->ev_db);
 	npc->ev_label_db->clear(npc->ev_label_db, npc->ev_label_db_clear_sub);
-
 	npc->npc_last_npd = NULL;
 	npc->npc_last_path = NULL;
 	npc->npc_last_ref = NULL;
+	
+	const int npc_new_min = npc->npc_id;
+	struct s_mapiterator *iter = mapit_geteachiddb();
 
-	//Remove all npcs/mobs. [Skotlex]
-	iter = mapit_geteachiddb();
-	for (bl = mapit->first(iter); mapit->exists(iter); bl = mapit->next(iter)) {
-		switch(bl->type) {
-			case BL_NPC:
-				if( bl->id != npc->fake_nd->bl.id )// don't remove fake_nd
-					npc->unload(BL_UCAST(BL_NPC, bl), false);
-				break;
-			case BL_MOB:
-				unit->free(bl,CLR_OUTSIGHT);
-				break;
+	/** Remove all NPCs/mobs. [Skotlex] **/
+	for (struct block_list *bl = mapit->first(iter); mapit->exists(iter); bl = mapit->next(iter)) {
+		switch (bl->type) {
+		case BL_NPC:
+			if (bl->id != npc->fake_nd->bl.id) /// Don't remove fake_nd.
+				npc->unload(BL_UCAST(BL_NPC, bl), false, false);
+
+			break;
+		case BL_MOB:
+			unit->free(bl, CLR_OUTSIGHT);
+			break;
+		default:
+			break;
 		}
 	}
+
 	mapit->free(iter);
 
-	if(battle_config.dynamic_mobs) {// dynamic check by [random]
-		int16 m;
-		for (m = 0; m < map->count; m++) {
-			int16 i;
-			for (i = 0; i < MAX_MOB_LIST_PER_MAP; i++) {
+	if (battle_config.dynamic_mobs) { /// Dynamic check. [random]
+		for (int m = 0; m < map->count; m++) {
+			for (int i = 0; i < MAX_MOB_LIST_PER_MAP; i++) {
 				if (map->list[m].moblist[i] != NULL) {
 					aFree(map->list[m].moblist[i]);
 					map->list[m].moblist[i] = NULL;
 				}
-				if( map->list[m].mob_delete_timer != INVALID_TIMER )
-				{ // Mobs were removed anyway,so delete the timer [Inkfish]
+
+				if (map->list[m].mob_delete_timer != INVALID_TIMER) { /// Mobs were removed anyway, so delete the timer. [Inkfish]
 					timer->delete(map->list[m].mob_delete_timer, map->removemobs_timer);
 					map->list[m].mob_delete_timer = INVALID_TIMER;
 				}
 			}
+
 			if (map->list[m].npc_num > 0)
-				ShowWarning("npc_reload: %d npcs weren't removed at map %s!\n", map->list[m].npc_num, map->list[m].name);
+				ShowWarning("npc_reload: %d NPCs weren't removed from map %s!\n",
+					    map->list[m].npc_num, map->list[m].name);
 		}
 	}
 
-	// clear mob spawn lookup index
 	mob->clear_spawninfo();
-
-	npc->npc_warp = npc->npc_shop = npc->npc_script = 0;
-	npc->npc_mob = npc->npc_cache_mob = npc->npc_delay_mob = 0;
-
-	// reset mapflags
+	npc->npc_warp = 0;
+	npc->npc_shop = 0;
+	npc->npc_script = 0;
+	npc->npc_mob = 0;
+	npc->npc_cache_mob = 0;
+	npc->npc_delay_mob = 0;
 	map->zone_reload();
 	map->flags_init();
-
-	// Reprocess npc files and reload constants
 	itemdb->name_constants();
 	clan->set_constants();
-	npc_process_files( npc_new_min );
-
+	npc_process_files(npc_new_min);
 	instance->reload();
-
 	map->zone_init();
-
-	npc->motd = npc->name2id("HerculesMOTD"); /* [Ind/Hercules] */
-
-	//Re-read the NPC Script Events cache.
+	npc->motd = npc->name2id("HerculesMOTD"); /// [Ind/Hercules]
 	npc->read_event_script();
 
-	// Execute main initialisation events
-	// The correct initialisation order is:
-	// OnInit -> OnInterIfInit -> OnInterIfInitOnce -> OnAgitInit -> OnAgitInit2
-	npc->event_do_oninit( true );
+	/**
+	 * Execute main initialization events
+	 * The correct initialization order is:
+	 * OnInit -> OnInterIfInit -> OnInterIfInitOnce -> OnAgitInit -> OnAgitInit2
+	 *
+	 **/
+	npc->event_do_oninit(true);
+
 	npc->market_fromsql();
 	npc->barter_fromsql();
 	npc->expanded_barter_fromsql();
-	// Execute rest of the startup events if connected to char-server. [Lance]
-	// Executed when connection is established with char-server in chrif_connectack
-	if( !intif->CheckForCharServer() ) {
-		ShowStatus("Event '"CL_WHITE"OnInterIfInit"CL_RESET"' executed with '"CL_WHITE"%d"CL_RESET"' NPCs.\n", npc->event_doall("OnInterIfInit"));
-		ShowStatus("Event '"CL_WHITE"OnInterIfInitOnce"CL_RESET"' executed with '"CL_WHITE"%d"CL_RESET"' NPCs.\n", npc->event_doall("OnInterIfInitOnce"));
-	}
-	// Refresh guild castle flags on both woe setups
-	// These events are only executed after receiving castle information from char-server
+
+	/*
+	 * Execute rest of the startup events if connected to char-server. [Lance]
+	 * Executed when connection is established with char-server in chrif_connectack().
+	 */
+	if (intif->CheckForCharServer() == 0) {
+		ShowStatus("Event '"CL_WHITE"OnInterIfInit"CL_RESET"' executed with '"CL_WHITE"%d"CL_RESET"' NPCs.\n",
+		           npc->event_doall("OnInterIfInit"));
+		ShowStatus("Event '"CL_WHITE"OnInterIfInitOnce"CL_RESET"' executed with '"CL_WHITE"%d"CL_RESET"' NPCs.\n",
+		           npc->event_doall("OnInterIfInitOnce"));
+	}
+
+	/*
+	 * Refresh guild castle flags on both WoE setups.
+	 * These events are only executed after receiving castle information from char-server.
+	 */
 	npc->event_doall("OnAgitInit");
 	npc->event_doall("OnAgitInit2");
 
 	return 0;
 }
 
-//Unload all npc in the given file
-static bool npc_unloadfile(const char *filepath)
+/**
+ * Unloads all NPCs in the given file.
+ *
+ * @param filepath Path to the file which should be unloaded.
+ * @param unload_mobs If true, mobs spawned by NPCs in the file will be removed.
+ * @return true if at least one NPC was unloaded, otherwise false.
+ *
+ **/
+static bool npc_unloadfile(const char *filepath, bool unload_mobs)
 {
+	nullpo_retr(false, filepath);
+
 	struct DBIterator *iter = db_iterator(npc->name_db);
-	struct npc_data* nd = NULL;
 	bool found = false;
 
-	nullpo_retr(false, filepath);
-
-	for( nd = dbi_first(iter); dbi_exists(iter); nd = dbi_next(iter) ) {
-		if( nd->path && strcasecmp(nd->path,filepath) == 0 ) { // FIXME: This can break in case-sensitive file systems
+	for (struct npc_data *nd = dbi_first(iter); dbi_exists(iter); nd = dbi_next(iter)) {
+		if (nd->path != NULL && strcasecmp(nd->path, filepath) == 0) { // FIXME: This can break in case-sensitive file systems.
 			found = true;
-			npc->unload_duplicates(nd);/* unload any npcs which could duplicate this but be in a different file */
-			npc->unload(nd, true);
+			npc->unload_duplicates(nd, unload_mobs); /// Unload any NPC which could duplicate this but be in a different file.
+			npc->unload(nd, true, unload_mobs);
 		}
 	}
 
 	dbi_destroy(iter);
 
-	if( found ) /* refresh event cache */
+	if (found) /// Refresh event cache.
 		npc->read_event_script();
 
 	return found;
@@ -5854,6 +5940,7 @@ void npc_defaults(void)
 	npc->unload_ev_label = npc_unload_ev_label;
 	npc->unload_dup_sub = npc_unload_dup_sub;
 	npc->unload_duplicates = npc_unload_duplicates;
+	npc->unload_mob = npc_unload_mob;
 	npc->unload = npc_unload;
 	npc->clearsrcfile = npc_clearsrcfile;
 	npc->addsrcfile = npc_addsrcfile;
diff --git a/src/map/npc.h b/src/map/npc.h
index 392911046..65c9796d9 100644
--- a/src/map/npc.h
+++ b/src/map/npc.h
@@ -270,8 +270,9 @@ struct npc_interface {
 	int (*unload_ev) (union DBKey key, struct DBData *data, va_list ap);
 	int (*unload_ev_label) (union DBKey key, struct DBData *data, va_list ap);
 	int (*unload_dup_sub) (struct npc_data *nd, va_list args);
-	void (*unload_duplicates) (struct npc_data *nd);
-	int (*unload) (struct npc_data *nd, bool single);
+	void (*unload_duplicates) (struct npc_data *nd, bool unload_mobs);
+	int (*unload_mob) (struct mob_data *md, va_list args);
+	int (*unload) (struct npc_data *nd, bool single, bool unload_mobs);
 	void (*clearsrcfile) (void);
 	void (*addsrcfile) (const char *name);
 	void (*delsrcfile) (const char *name);
@@ -313,7 +314,7 @@ struct npc_interface {
 	int (*path_db_clear_sub) (union DBKey key, struct DBData *data, va_list args);
 	int (*ev_label_db_clear_sub) (union DBKey key, struct DBData *data, va_list args);
 	int (*reload) (void);
-	bool (*unloadfile) (const char *filepath);
+	bool (*unloadfile) (const char *filepath, bool unload_mobs);
 	void (*do_clear_npc) (void);
 	void (*debug_warps_sub) (struct npc_data *nd);
 	void (*debug_warps) (void);
diff --git a/src/map/script.c b/src/map/script.c
index 3879d8efb..b89176dba 100644
--- a/src/map/script.c
+++ b/src/map/script.c
@@ -14576,47 +14576,53 @@ static BUILDIN(strmobinfo)
 	return true;
 }
 
-/*==========================================
- * Summon guardians [Valaris]
- * guardian("<map name>",<x>,<y>,"<name to show>",<mob id>{,"<event label>"}{,<guardian index>}) -> <id>
- *------------------------------------------*/
+/**
+ * Summons a castle guardian mob.
+ *
+ * @code{.herc}
+ *	guardian("<map name>", <x>, <y>, "<name to show>", <mob id>{, <guardian index>});
+ *	guardian("<map name>", <x>, <y>, "<name to show>", <mob id>{, "<event label>"{, <guardian index>}});
+ * @endcode
+ *
+ * @author Valaris
+ *
+ **/
 static BUILDIN(guardian)
 {
-	int class_ = 0, x = 0, y = 0, guardian = 0;
-	const char *str, *mapname, *evt="";
 	bool has_index = false;
+	int guardian = 0;
+	const char *event = "";
 
-	mapname = script_getstr(st,2);
-	x       = script_getnum(st,3);
-	y       = script_getnum(st,4);
-	str     = script_getstr(st,5);
-	class_  = script_getnum(st,6);
-
-	if( script_hasdata(st,8) )
-	{// "<event label>",<guardian index>
-		evt=script_getstr(st,7);
-		guardian=script_getnum(st,8);
+	if (script_hasdata(st, 8)) { /// "<event label>", <guardian index>
+		event = script_getstr(st, 7);
+		script->check_event(st, event);
+		guardian = script_getnum(st, 8);
 		has_index = true;
-	} else if( script_hasdata(st,7) ) {
-		struct script_data *data = script_getdata(st,7);
-		script->get_val(st,data); // Dereference if it's a variable
-		if( data_isstring(data) ) {
-			// "<event label>"
-			evt=script_getstr(st,7);
-		} else if( data_isint(data) ) {
-			// <guardian index>
-			guardian=script_getnum(st,7);
+	} else if (script_hasdata(st, 7)) {
+		struct script_data *data = script_getdata(st, 7);
+
+		script->get_val(st, data); /// Dereference if it's a variable.
+
+		if (data_isstring(data)) { /// "<event label>"
+			event = script_getstr(st, 7);
+			script->check_event(st, event);
+		} else if (data_isint(data)) { /// <guardian index>
+			guardian = script_getnum(st, 7);
 			has_index = true;
 		} else {
-			ShowError("script:guardian: invalid data type for argument #6 (from 1)\n");
+			ShowError("script:guardian: Invalid data type for argument #6!\n");
 			script->reportdata(data);
 			return false;
 		}
 	}
 
-	script->check_event(st, evt);
-	script_pushint(st, mob->spawn_guardian(mapname,x,y,str,class_,evt,guardian,has_index));
+	const char *mapname = script_getstr(st, 2);
+	const char *name = script_getstr(st, 5);
+	const int x = script_getnum(st, 3);
+	const int y = script_getnum(st, 4);
+	const int mob_id = script_getnum(st, 6);
 
+	script_pushint(st, mob->spawn_guardian(mapname, x, y, name, mob_id, event, guardian, has_index, st->oid));
 	return true;
 }
 /*==========================================
@@ -16944,38 +16950,54 @@ static BUILDIN(logmes)
 	return true;
 }
 
+/**
+ * Summons a mob which will act as a slave for the invoking character.
+ *
+ * @code{.herc}
+ *	summon("mob name", <mob id>{, <timeout>{, "event label"}});
+ * @endcode
+ *
+ * @author Celest
+ *
+ **/
 static BUILDIN(summon)
 {
-	int class_, timeout=0;
-	const char *str,*event="";
-	struct mob_data *md;
-	int64 tick = timer->gettick();
 	struct map_session_data *sd = script->rid2sd(st);
+
 	if (sd == NULL)
 		return true;
 
-	str    = script_getstr(st,2);
-	class_ = script_getnum(st,3);
-	if( script_hasdata(st,4) )
-		timeout=script_getnum(st,4);
-	if( script_hasdata(st,5) ) {
-		event=script_getstr(st,5);
+	const int64 tick = timer->gettick();
+
+	clif->skill_poseffect(&sd->bl, AM_CALLHOMUN, 1, sd->bl.x, sd->bl.y, tick);
+
+	const char *event = "";
+
+	if (script_hasdata(st, 5)) {
+		event = script_getstr(st, 5);
 		script->check_event(st, event);
 	}
 
-	clif->skill_poseffect(&sd->bl,AM_CALLHOMUN,1,sd->bl.x,sd->bl.y,tick);
+	const char *name = script_getstr(st, 2);
+	const int mob_id = script_getnum(st, 3);
+	struct mob_data *md = mob->once_spawn_sub(&sd->bl, sd->bl.m, sd->bl.x, sd->bl.y, name, mob_id, event,
+						  SZ_SMALL, AI_NONE, 0);
 
-	md = mob->once_spawn_sub(&sd->bl, sd->bl.m, sd->bl.x, sd->bl.y, str, class_, event, SZ_SMALL, AI_NONE);
-	if (md) {
-		md->master_id=sd->bl.id;
+	if (md != NULL) {
+		md->master_id = sd->bl.id;
 		md->special_state.ai = AI_ATTACK;
-		if( md->deletetimer != INVALID_TIMER )
+
+		if (md->deletetimer != INVALID_TIMER)
 			timer->delete(md->deletetimer, mob->timer_delete);
-		md->deletetimer = timer->add(tick+(timeout>0?timeout*1000:60000),mob->timer_delete,md->bl.id,0);
-		mob->spawn (md); //Now it is ready for spawning.
-		clif->specialeffect(&md->bl,344,AREA);
+
+		const int timeout = script_hasdata(st, 4) ? script_getnum(st, 4) * 1000 : 60000;
+
+		md->deletetimer = timer->add(tick + ((timeout == 0) ? 60000 : timeout), mob->timer_delete, md->bl.id, 0);
+		mob->spawn(md);
+		clif->specialeffect(&md->bl, 344, AREA);
 		sc_start4(NULL, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 60000);
 	}
+
 	return true;
 }
 
@@ -22407,20 +22429,31 @@ static BUILDIN(bg_warp)
 	return true;
 }
 
+/**
+ * Spawns a mob with allegiance to the given battle group.
+ *
+ * @code{.herc}
+ *	bg_monster(<battle group>, "<map name>", <x>, <y>, "<name to show>", <mob id>{, "<event label>"});
+ * @endcode
+ *
+ **/
 static BUILDIN(bg_monster)
 {
-	int class_ = 0, x = 0, y = 0, bg_id = 0;
-	const char *str, *mapname, *evt="";
-
-	bg_id   = script_getnum(st,2);
-	mapname = script_getstr(st,3);
-	x       = script_getnum(st,4);
-	y       = script_getnum(st,5);
-	str     = script_getstr(st,6);
-	class_  = script_getnum(st,7);
-	if( script_hasdata(st,8) ) evt = script_getstr(st,8);
-	script->check_event(st, evt);
-	script_pushint(st, mob->spawn_bg(mapname,x,y,str,class_,evt,bg_id));
+	const char *event = "";
+
+	if (script_hasdata(st, 8)) {
+		event = script_getstr(st, 8);
+		script->check_event(st, event);
+	}
+
+	const char *mapname = script_getstr(st, 3);
+	const char *name = script_getstr(st, 6);
+	const int bg_id = script_getnum(st, 2);
+	const int x = script_getnum(st, 4);
+	const int y = script_getnum(st, 5);
+	const int mob_id = script_getnum(st, 7);
+
+	script_pushint(st, mob->spawn_bg(mapname, x, y, name, mob_id, event, bg_id, st->oid));
 	return true;
 }
 
diff --git a/src/map/skill.c b/src/map/skill.c
index 09e216804..a488e3eaf 100644
--- a/src/map/skill.c
+++ b/src/map/skill.c
@@ -10417,7 +10417,7 @@ static int skill_castend_nodamage_id(struct block_list *src, struct block_list *
 			if(sd) {
 				struct mob_data *summon_md;
 
-				summon_md = mob->once_spawn_sub(src, src->m, src->x, src->y, clif->get_bl_name(src), MOBID_KO_KAGE, "", SZ_SMALL, AI_NONE);
+				summon_md = mob->once_spawn_sub(src, src->m, src->x, src->y, clif->get_bl_name(src), MOBID_KO_KAGE, "", SZ_SMALL, AI_NONE, 0);
 				if( summon_md ) {
 					summon_md->master_id = src->id;
 					summon_md->special_state.ai = AI_ZANZOU;
@@ -10600,7 +10600,7 @@ static int skill_castend_nodamage_id(struct block_list *src, struct block_list *
 
 			for (i = 0; i < summons[skill_lv-1].quantity; i++) {
 				struct mob_data *summon_md = mob->once_spawn_sub(src, src->m, src->x, src->y, clif->get_bl_name(src),
-				                                                 summons[skill_lv-1].mob_id, "", SZ_SMALL, AI_ATTACK);
+				                                                 summons[skill_lv-1].mob_id, "", SZ_SMALL, AI_ATTACK, 0);
 				if (summon_md != NULL) {
 					summon_md->master_id = src->id;
 					if (summon_md->deletetimer != INVALID_TIMER)
@@ -11383,7 +11383,7 @@ static int skill_castend_pos2(struct block_list *src, int x, int y, uint16 skill
 				}
 
 				// Correct info, don't change any of this! [Celest]
-				md = mob->once_spawn_sub(src, src->m, x, y, clif->get_bl_name(src), class_, "", SZ_SMALL, AI_NONE);
+				md = mob->once_spawn_sub(src, src->m, x, y, clif->get_bl_name(src), class_, "", SZ_SMALL, AI_NONE, 0);
 				if (md) {
 					md->master_id = src->id;
 					md->special_state.ai = (skill_id == AM_SPHEREMINE) ? AI_SPHERE : AI_FLORA;
@@ -11485,7 +11485,7 @@ static int skill_castend_pos2(struct block_list *src, int x, int y, uint16 skill
 					clif->skill_fail(sd, skill_id, USESKILL_FAIL_LEVEL, 0, 0);
 				} else {
 					int mob_id = skill_lv < 2 ? MOBID_BLACK_MUSHROOM + rnd()%2 : MOBID_RED_PLANT + rnd()%6;
-					struct mob_data *md = mob->once_spawn_sub(src, src->m, x, y, DEFAULT_MOB_JNAME, mob_id, "", SZ_SMALL, AI_NONE);
+					struct mob_data *md = mob->once_spawn_sub(src, src->m, x, y, DEFAULT_MOB_JNAME, mob_id, "", SZ_SMALL, AI_NONE, 0);
 					int i;
 					if (md == NULL)
 						break;
@@ -11631,7 +11631,7 @@ static int skill_castend_pos2(struct block_list *src, int x, int y, uint16 skill
 
 		case NC_SILVERSNIPER:
 			{
-				struct mob_data *md = mob->once_spawn_sub(src, src->m, x, y, clif->get_bl_name(src), MOBID_SILVERSNIPER, "", SZ_SMALL, AI_NONE);
+				struct mob_data *md = mob->once_spawn_sub(src, src->m, x, y, clif->get_bl_name(src), MOBID_SILVERSNIPER, "", SZ_SMALL, AI_NONE, 0);
 				if (md) {
 					md->master_id = src->id;
 					md->special_state.ai = AI_FLORA;
@@ -18793,7 +18793,7 @@ static int skill_magicdecoy(struct map_session_data *sd, int nameid)
 		break;
 	}
 
-	md = mob->once_spawn_sub(&sd->bl, sd->bl.m, x, y, sd->status.name, class_, "", SZ_SMALL, AI_NONE);
+	md = mob->once_spawn_sub(&sd->bl, sd->bl.m, x, y, sd->status.name, class_, "", SZ_SMALL, AI_NONE, 0);
 	if( md ) {
 		md->master_id = sd->bl.id;
 		md->special_state.ai = AI_FLORA;
diff --git a/src/plugins/HPMHooking/HPMHooking.Defs.inc b/src/plugins/HPMHooking/HPMHooking.Defs.inc
index 206934222..8c6f43433 100644
--- a/src/plugins/HPMHooking/HPMHooking.Defs.inc
+++ b/src/plugins/HPMHooking/HPMHooking.Defs.inc
@@ -5336,22 +5336,22 @@ typedef struct view_data* (*HPMHOOK_pre_mob_get_viewdata) (int *class_);
 typedef struct view_data* (*HPMHOOK_post_mob_get_viewdata) (struct view_data* retVal___, int class_);
 typedef int (*HPMHOOK_pre_mob_parse_dataset) (struct spawn_data **data);
 typedef int (*HPMHOOK_post_mob_parse_dataset) (int retVal___, struct spawn_data *data);
-typedef struct mob_data* (*HPMHOOK_pre_mob_spawn_dataset) (struct spawn_data **data);
-typedef struct mob_data* (*HPMHOOK_post_mob_spawn_dataset) (struct mob_data* retVal___, struct spawn_data *data);
+typedef struct mob_data* (*HPMHOOK_pre_mob_spawn_dataset) (struct spawn_data **data, int *npc_id);
+typedef struct mob_data* (*HPMHOOK_post_mob_spawn_dataset) (struct mob_data* retVal___, struct spawn_data *data, int npc_id);
 typedef int (*HPMHOOK_pre_mob_get_random_id) (int *type, int *flag, int *lv);
 typedef int (*HPMHOOK_post_mob_get_random_id) (int retVal___, int type, int flag, int lv);
 typedef bool (*HPMHOOK_pre_mob_ksprotected) (struct block_list **src, struct block_list **target);
 typedef bool (*HPMHOOK_post_mob_ksprotected) (bool retVal___, struct block_list *src, struct block_list *target);
-typedef struct mob_data* (*HPMHOOK_pre_mob_once_spawn_sub) (struct block_list **bl, int16 *m, int16 *x, int16 *y, const char **mobname, int *class_, const char **event, unsigned int *size, unsigned int *ai);
-typedef struct mob_data* (*HPMHOOK_post_mob_once_spawn_sub) (struct mob_data* retVal___, struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai);
+typedef struct mob_data* (*HPMHOOK_pre_mob_once_spawn_sub) (struct block_list **bl, int16 *m, int16 *x, int16 *y, const char **mobname, int *class_, const char **event, unsigned int *size, unsigned int *ai, int *npc_id);
+typedef struct mob_data* (*HPMHOOK_post_mob_once_spawn_sub) (struct mob_data* retVal___, struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai, int npc_id);
 typedef int (*HPMHOOK_pre_mob_once_spawn) (struct map_session_data **sd, int16 *m, int16 *x, int16 *y, const char **mobname, int *class_, int *amount, const char **event, unsigned int *size, unsigned int *ai);
 typedef int (*HPMHOOK_post_mob_once_spawn) (int retVal___, struct map_session_data *sd, int16 m, int16 x, int16 y, const char *mobname, int class_, int amount, const char *event, unsigned int size, unsigned int ai);
 typedef int (*HPMHOOK_pre_mob_once_spawn_area) (struct map_session_data **sd, int16 *m, int16 *x0, int16 *y0, int16 *x1, int16 *y1, const char **mobname, int *class_, int *amount, const char **event, unsigned int *size, unsigned int *ai);
 typedef int (*HPMHOOK_post_mob_once_spawn_area) (int retVal___, struct map_session_data *sd, int16 m, int16 x0, int16 y0, int16 x1, int16 y1, const char *mobname, int class_, int amount, const char *event, unsigned int size, unsigned int ai);
-typedef int (*HPMHOOK_pre_mob_spawn_guardian) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, int *guardian, bool *has_index);
-typedef int (*HPMHOOK_post_mob_spawn_guardian) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index);
-typedef int (*HPMHOOK_pre_mob_spawn_bg) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, unsigned int *bg_id);
-typedef int (*HPMHOOK_post_mob_spawn_bg) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id);
+typedef int (*HPMHOOK_pre_mob_spawn_guardian) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, int *guardian, bool *has_index, int *npc_id);
+typedef int (*HPMHOOK_post_mob_spawn_guardian) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index, int npc_id);
+typedef int (*HPMHOOK_pre_mob_spawn_bg) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, unsigned int *bg_id, int *npc_id);
+typedef int (*HPMHOOK_post_mob_spawn_bg) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id, int npc_id);
 typedef int (*HPMHOOK_pre_mob_can_reach) (struct mob_data **md, struct block_list **bl, int *range, int *state);
 typedef int (*HPMHOOK_post_mob_can_reach) (int retVal___, struct mob_data *md, struct block_list *bl, int range, int state);
 typedef int (*HPMHOOK_pre_mob_linksearch) (struct block_list **bl, va_list ap);
@@ -5686,10 +5686,12 @@ typedef int (*HPMHOOK_pre_npc_unload_ev_label) (union DBKey *key, struct DBData
 typedef int (*HPMHOOK_post_npc_unload_ev_label) (int retVal___, union DBKey key, struct DBData *data, va_list ap);
 typedef int (*HPMHOOK_pre_npc_unload_dup_sub) (struct npc_data **nd, va_list args);
 typedef int (*HPMHOOK_post_npc_unload_dup_sub) (int retVal___, struct npc_data *nd, va_list args);
-typedef void (*HPMHOOK_pre_npc_unload_duplicates) (struct npc_data **nd);
-typedef void (*HPMHOOK_post_npc_unload_duplicates) (struct npc_data *nd);
-typedef int (*HPMHOOK_pre_npc_unload) (struct npc_data **nd, bool *single);
-typedef int (*HPMHOOK_post_npc_unload) (int retVal___, struct npc_data *nd, bool single);
+typedef void (*HPMHOOK_pre_npc_unload_duplicates) (struct npc_data **nd, bool *unload_mobs);
+typedef void (*HPMHOOK_post_npc_unload_duplicates) (struct npc_data *nd, bool unload_mobs);
+typedef int (*HPMHOOK_pre_npc_unload_mob) (struct mob_data **md, va_list args);
+typedef int (*HPMHOOK_post_npc_unload_mob) (int retVal___, struct mob_data *md, va_list args);
+typedef int (*HPMHOOK_pre_npc_unload) (struct npc_data **nd, bool *single, bool *unload_mobs);
+typedef int (*HPMHOOK_post_npc_unload) (int retVal___, struct npc_data *nd, bool single, bool unload_mobs;
 typedef void (*HPMHOOK_pre_npc_clearsrcfile) (void);
 typedef void (*HPMHOOK_post_npc_clearsrcfile) (void);
 typedef void (*HPMHOOK_pre_npc_addsrcfile) (const char **name);
@@ -5772,8 +5774,8 @@ typedef int (*HPMHOOK_pre_npc_ev_label_db_clear_sub) (union DBKey *key, struct D
 typedef int (*HPMHOOK_post_npc_ev_label_db_clear_sub) (int retVal___, union DBKey key, struct DBData *data, va_list args);
 typedef int (*HPMHOOK_pre_npc_reload) (void);
 typedef int (*HPMHOOK_post_npc_reload) (int retVal___);
-typedef bool (*HPMHOOK_pre_npc_unloadfile) (const char **filepath);
-typedef bool (*HPMHOOK_post_npc_unloadfile) (bool retVal___, const char *filepath);
+typedef bool (*HPMHOOK_pre_npc_unloadfile) (const char **filepath, bool *unload_mobs);
+typedef bool (*HPMHOOK_post_npc_unloadfile) (bool retVal___, const char *filepath, bool unload_mobs);
 typedef void (*HPMHOOK_pre_npc_do_clear_npc) (void);
 typedef void (*HPMHOOK_post_npc_do_clear_npc) (void);
 typedef void (*HPMHOOK_pre_npc_debug_warps_sub) (struct npc_data **nd);
diff --git a/src/plugins/HPMHooking/HPMHooking_map.HPMHooksCore.inc b/src/plugins/HPMHooking/HPMHooking_map.HPMHooksCore.inc
index d70ee0024..53ba3403c 100644
--- a/src/plugins/HPMHooking/HPMHooking_map.HPMHooksCore.inc
+++ b/src/plugins/HPMHooking/HPMHooking_map.HPMHooksCore.inc
@@ -4280,6 +4280,8 @@ struct {
 	struct HPMHookPoint *HP_npc_unload_dup_sub_post;
 	struct HPMHookPoint *HP_npc_unload_duplicates_pre;
 	struct HPMHookPoint *HP_npc_unload_duplicates_post;
+	struct HPMHookPoint *HP_npc_unload_mob_pre;
+	struct HPMHookPoint *HP_npc_unload_mob_post;
 	struct HPMHookPoint *HP_npc_unload_pre;
 	struct HPMHookPoint *HP_npc_unload_post;
 	struct HPMHookPoint *HP_npc_clearsrcfile_pre;
@@ -11145,6 +11147,8 @@ struct {
 	int HP_npc_unload_dup_sub_post;
 	int HP_npc_unload_duplicates_pre;
 	int HP_npc_unload_duplicates_post;
+	int HP_npc_unload_mob_pre;
+	int HP_npc_unload_mob_post;
 	int HP_npc_unload_pre;
 	int HP_npc_unload_post;
 	int HP_npc_clearsrcfile_pre;
diff --git a/src/plugins/HPMHooking/HPMHooking_map.HookingPoints.inc b/src/plugins/HPMHooking/HPMHooking_map.HookingPoints.inc
index c755e0bec..0904a1dac 100644
--- a/src/plugins/HPMHooking/HPMHooking_map.HookingPoints.inc
+++ b/src/plugins/HPMHooking/HPMHooking_map.HookingPoints.inc
@@ -2192,6 +2192,7 @@ struct HookingPointData HookingPoints[] = {
 	{ HP_POP(npc->unload_ev_label, HP_npc_unload_ev_label) },
 	{ HP_POP(npc->unload_dup_sub, HP_npc_unload_dup_sub) },
 	{ HP_POP(npc->unload_duplicates, HP_npc_unload_duplicates) },
+	{ HP_POP(npc->unload_mob, HP_npc_unload_mob) },
 	{ HP_POP(npc->unload, HP_npc_unload) },
 	{ HP_POP(npc->clearsrcfile, HP_npc_clearsrcfile) },
 	{ HP_POP(npc->addsrcfile, HP_npc_addsrcfile) },
diff --git a/src/plugins/HPMHooking/HPMHooking_map.Hooks.inc b/src/plugins/HPMHooking/HPMHooking_map.Hooks.inc
index d0ddcf28a..319e675a8 100644
--- a/src/plugins/HPMHooking/HPMHooking_map.Hooks.inc
+++ b/src/plugins/HPMHooking/HPMHooking_map.Hooks.inc
@@ -52053,15 +52053,15 @@ int HP_mob_parse_dataset(struct spawn_data *data) {
 	}
 	return retVal___;
 }
-struct mob_data* HP_mob_spawn_dataset(struct spawn_data *data) {
+struct mob_data* HP_mob_spawn_dataset(struct spawn_data *data, int npc_id) {
 	int hIndex = 0;
 	struct mob_data* retVal___ = NULL;
 	if (HPMHooks.count.HP_mob_spawn_dataset_pre > 0) {
-		struct mob_data* (*preHookFunc) (struct spawn_data **data);
+		struct mob_data* (*preHookFunc) (struct spawn_data **data, int *npc_id);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_dataset_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_mob_spawn_dataset_pre[hIndex].func;
-			retVal___ = preHookFunc(&data);
+			retVal___ = preHookFunc(&data, &npc_id);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -52069,13 +52069,13 @@ struct mob_data* HP_mob_spawn_dataset(struct spawn_data *data) {
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.mob.spawn_dataset(data);
+		retVal___ = HPMHooks.source.mob.spawn_dataset(data, npc_id);
 	}
 	if (HPMHooks.count.HP_mob_spawn_dataset_post > 0) {
-		struct mob_data* (*postHookFunc) (struct mob_data* retVal___, struct spawn_data *data);
+		struct mob_data* (*postHookFunc) (struct mob_data* retVal___, struct spawn_data *data, int npc_id);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_dataset_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_mob_spawn_dataset_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, data);
+			retVal___ = postHookFunc(retVal___, data, npc_id);
 		}
 	}
 	return retVal___;
@@ -52134,15 +52134,15 @@ bool HP_mob_ksprotected(struct block_list *src, struct block_list *target) {
 	}
 	return retVal___;
 }
-struct mob_data* HP_mob_once_spawn_sub(struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai) {
+struct mob_data* HP_mob_once_spawn_sub(struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai, int npc_id) {
 	int hIndex = 0;
 	struct mob_data* retVal___ = NULL;
 	if (HPMHooks.count.HP_mob_once_spawn_sub_pre > 0) {
-		struct mob_data* (*preHookFunc) (struct block_list **bl, int16 *m, int16 *x, int16 *y, const char **mobname, int *class_, const char **event, unsigned int *size, unsigned int *ai);
+		struct mob_data* (*preHookFunc) (struct block_list **bl, int16 *m, int16 *x, int16 *y, const char **mobname, int *class_, const char **event, unsigned int *size, unsigned int *ai, int *npc_id);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_once_spawn_sub_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_mob_once_spawn_sub_pre[hIndex].func;
-			retVal___ = preHookFunc(&bl, &m, &x, &y, &mobname, &class_, &event, &size, &ai);
+			retVal___ = preHookFunc(&bl, &m, &x, &y, &mobname, &class_, &event, &size, &ai, &npc_id);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -52150,13 +52150,13 @@ struct mob_data* HP_mob_once_spawn_sub(struct block_list *bl, int16 m, int16 x,
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.mob.once_spawn_sub(bl, m, x, y, mobname, class_, event, size, ai);
+		retVal___ = HPMHooks.source.mob.once_spawn_sub(bl, m, x, y, mobname, class_, event, size, ai, npc_id);
 	}
 	if (HPMHooks.count.HP_mob_once_spawn_sub_post > 0) {
-		struct mob_data* (*postHookFunc) (struct mob_data* retVal___, struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai);
+		struct mob_data* (*postHookFunc) (struct mob_data* retVal___, struct block_list *bl, int16 m, int16 x, int16 y, const char *mobname, int class_, const char *event, unsigned int size, unsigned int ai, int npc_id);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_once_spawn_sub_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_mob_once_spawn_sub_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, bl, m, x, y, mobname, class_, event, size, ai);
+			retVal___ = postHookFunc(retVal___, bl, m, x, y, mobname, class_, event, size, ai, npc_id);
 		}
 	}
 	return retVal___;
@@ -52215,15 +52215,15 @@ int HP_mob_once_spawn_area(struct map_session_data *sd, int16 m, int16 x0, int16
 	}
 	return retVal___;
 }
-int HP_mob_spawn_guardian(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index) {
+int HP_mob_spawn_guardian(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index, int npc_id) {
 	int hIndex = 0;
 	int retVal___ = 0;
 	if (HPMHooks.count.HP_mob_spawn_guardian_pre > 0) {
-		int (*preHookFunc) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, int *guardian, bool *has_index);
+		int (*preHookFunc) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, int *guardian, bool *has_index, int *npc_id);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_guardian_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_mob_spawn_guardian_pre[hIndex].func;
-			retVal___ = preHookFunc(&mapname, &x, &y, &mobname, &class_, &event, &guardian, &has_index);
+			retVal___ = preHookFunc(&mapname, &x, &y, &mobname, &class_, &event, &guardian, &has_index, &npc_id);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -52231,26 +52231,26 @@ int HP_mob_spawn_guardian(const char *mapname, short x, short y, const char *mob
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.mob.spawn_guardian(mapname, x, y, mobname, class_, event, guardian, has_index);
+		retVal___ = HPMHooks.source.mob.spawn_guardian(mapname, x, y, mobname, class_, event, guardian, has_index, npc_id);
 	}
 	if (HPMHooks.count.HP_mob_spawn_guardian_post > 0) {
-		int (*postHookFunc) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index);
+		int (*postHookFunc) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, int guardian, bool has_index, int npc_id);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_guardian_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_mob_spawn_guardian_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, mapname, x, y, mobname, class_, event, guardian, has_index);
+			retVal___ = postHookFunc(retVal___, mapname, x, y, mobname, class_, event, guardian, has_index, npc_id);
 		}
 	}
 	return retVal___;
 }
-int HP_mob_spawn_bg(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id) {
+int HP_mob_spawn_bg(const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id, int npc_id) {
 	int hIndex = 0;
 	int retVal___ = 0;
 	if (HPMHooks.count.HP_mob_spawn_bg_pre > 0) {
-		int (*preHookFunc) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, unsigned int *bg_id);
+		int (*preHookFunc) (const char **mapname, short *x, short *y, const char **mobname, int *class_, const char **event, unsigned int *bg_id, int *npc_id);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_bg_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_mob_spawn_bg_pre[hIndex].func;
-			retVal___ = preHookFunc(&mapname, &x, &y, &mobname, &class_, &event, &bg_id);
+			retVal___ = preHookFunc(&mapname, &x, &y, &mobname, &class_, &event, &bg_id, &npc_id);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -52258,13 +52258,13 @@ int HP_mob_spawn_bg(const char *mapname, short x, short y, const char *mobname,
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.mob.spawn_bg(mapname, x, y, mobname, class_, event, bg_id);
+		retVal___ = HPMHooks.source.mob.spawn_bg(mapname, x, y, mobname, class_, event, bg_id, npc_id);
 	}
 	if (HPMHooks.count.HP_mob_spawn_bg_post > 0) {
-		int (*postHookFunc) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id);
+		int (*postHookFunc) (int retVal___, const char *mapname, short x, short y, const char *mobname, int class_, const char *event, unsigned int bg_id, int npc_id);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_mob_spawn_bg_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_mob_spawn_bg_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, mapname, x, y, mobname, class_, event, bg_id);
+			retVal___ = postHookFunc(retVal___, mapname, x, y, mobname, class_, event, bg_id, npc_id);
 		}
 	}
 	return retVal___;
@@ -56811,14 +56811,14 @@ int HP_npc_unload_dup_sub(struct npc_data *nd, va_list args) {
 	}
 	return retVal___;
 }
-void HP_npc_unload_duplicates(struct npc_data *nd) {
+void HP_npc_unload_duplicates(struct npc_data *nd, bool unload_mobs) {
 	int hIndex = 0;
 	if (HPMHooks.count.HP_npc_unload_duplicates_pre > 0) {
-		void (*preHookFunc) (struct npc_data **nd);
+		void (*preHookFunc) (struct npc_data **nd, bool *unload_mobs);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_duplicates_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_npc_unload_duplicates_pre[hIndex].func;
-			preHookFunc(&nd);
+			preHookFunc(&nd, &unload_mobs);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -56826,26 +56826,59 @@ void HP_npc_unload_duplicates(struct npc_data *nd) {
 		}
 	}
 	{
-		HPMHooks.source.npc.unload_duplicates(nd);
+		HPMHooks.source.npc.unload_duplicates(nd, unload_mobs);
 	}
 	if (HPMHooks.count.HP_npc_unload_duplicates_post > 0) {
-		void (*postHookFunc) (struct npc_data *nd);
+		void (*postHookFunc) (struct npc_data *nd, bool unload_mobs);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_duplicates_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_npc_unload_duplicates_post[hIndex].func;
-			postHookFunc(nd);
+			postHookFunc(nd, unload_mobs);
 		}
 	}
 	return;
 }
-int HP_npc_unload(struct npc_data *nd, bool single) {
+int HP_npc_unload_mob(struct mob_data *md, va_list args) {
+	int hIndex = 0;
+	int retVal___ = 0;
+	if (HPMHooks.count.HP_npc_unload_mob_pre > 0) {
+		int (*preHookFunc) (struct mob_data **md, va_list args);
+		*HPMforce_return = false;
+		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_mob_pre; hIndex++) {
+			va_list args___copy; va_copy(args___copy, args);
+			preHookFunc = HPMHooks.list.HP_npc_unload_mob_pre[hIndex].func;
+			retVal___ = preHookFunc(&md, args___copy);
+			va_end(args___copy);
+		}
+		if (*HPMforce_return) {
+			*HPMforce_return = false;
+			return retVal___;
+		}
+	}
+	{
+		va_list args___copy; va_copy(args___copy, args);
+		retVal___ = HPMHooks.source.npc.unload_mob(md, args___copy);
+		va_end(args___copy);
+	}
+	if (HPMHooks.count.HP_npc_unload_mob_post > 0) {
+		int (*postHookFunc) (int retVal___, struct mob_data *md, va_list args);
+		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_mob_post; hIndex++) {
+			va_list args___copy; va_copy(args___copy, args);
+			postHookFunc = HPMHooks.list.HP_npc_unload_mob_post[hIndex].func;
+			retVal___ = postHookFunc(retVal___, md, args___copy);
+			va_end(args___copy);
+		}
+	}
+	return retVal___;
+}
+int HP_npc_unload(struct npc_data *nd, bool single, bool unload_mobs) {
 	int hIndex = 0;
 	int retVal___ = 0;
 	if (HPMHooks.count.HP_npc_unload_pre > 0) {
-		int (*preHookFunc) (struct npc_data **nd, bool *single);
+		int (*preHookFunc) (struct npc_data **nd, bool *single, bool *unload_mobs);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_npc_unload_pre[hIndex].func;
-			retVal___ = preHookFunc(&nd, &single);
+			retVal___ = preHookFunc(&nd, &single, &unload_mobs);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -56853,13 +56886,13 @@ int HP_npc_unload(struct npc_data *nd, bool single) {
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.npc.unload(nd, single);
+		retVal___ = HPMHooks.source.npc.unload(nd, single, unload_mobs);
 	}
 	if (HPMHooks.count.HP_npc_unload_post > 0) {
-		int (*postHookFunc) (int retVal___, struct npc_data *nd, bool single);
+		int (*postHookFunc) (int retVal___, struct npc_data *nd, bool single, bool unload_mobs);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unload_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_npc_unload_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, nd, single);
+			retVal___ = postHookFunc(retVal___, nd, single, unload_mobs);
 		}
 	}
 	return retVal___;
@@ -57974,15 +58007,15 @@ int HP_npc_reload(void) {
 	}
 	return retVal___;
 }
-bool HP_npc_unloadfile(const char *filepath) {
+bool HP_npc_unloadfile(const char *filepath, bool unload_mobs) {
 	int hIndex = 0;
 	bool retVal___ = false;
 	if (HPMHooks.count.HP_npc_unloadfile_pre > 0) {
-		bool (*preHookFunc) (const char **filepath);
+		bool (*preHookFunc) (const char **filepath, bool *unload_mobs);
 		*HPMforce_return = false;
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unloadfile_pre; hIndex++) {
 			preHookFunc = HPMHooks.list.HP_npc_unloadfile_pre[hIndex].func;
-			retVal___ = preHookFunc(&filepath);
+			retVal___ = preHookFunc(&filepath, &unload_mobs);
 		}
 		if (*HPMforce_return) {
 			*HPMforce_return = false;
@@ -57990,13 +58023,13 @@ bool HP_npc_unloadfile(const char *filepath) {
 		}
 	}
 	{
-		retVal___ = HPMHooks.source.npc.unloadfile(filepath);
+		retVal___ = HPMHooks.source.npc.unloadfile(filepath, unload_mobs);
 	}
 	if (HPMHooks.count.HP_npc_unloadfile_post > 0) {
-		bool (*postHookFunc) (bool retVal___, const char *filepath);
+		bool (*postHookFunc) (bool retVal___, const char *filepath, bool unload_mobs);
 		for (hIndex = 0; hIndex < HPMHooks.count.HP_npc_unloadfile_post; hIndex++) {
 			postHookFunc = HPMHooks.list.HP_npc_unloadfile_post[hIndex].func;
-			retVal___ = postHookFunc(retVal___, filepath);
+			retVal___ = postHookFunc(retVal___, filepath, unload_mobs);
 		}
 	}
 	return retVal___;