diff --git a/asm/include/overlay_29_022F73EC.inc b/asm/include/overlay_29_022F740C.inc
similarity index 86%
rename from asm/include/overlay_29_022F73EC.inc
rename to asm/include/overlay_29_022F740C.inc
index 7062ff89..783b5d91 100644
--- a/asm/include/overlay_29_022F73EC.inc
+++ b/asm/include/overlay_29_022F740C.inc
@@ -1,7 +1,6 @@
 #pragma once
 .public DUNGEON_PTR
 .public DirectoryFileMngr_GetDirectoryFileSize
-.public FloorNumberIsEven
 .public GendersEqualNotGenderless
 .public GetMonsterGender
 .public GetSpriteFileSize
@@ -10,6 +9,5 @@
 .public LoadWanTableEntryFromPack
 .public LoadWanTableEntryFromPackUseProvidedMemory
 .public MemAlloc
-.public ReplaceWanFromBinFile
 .public WAN_TABLE
 .public ov29_0237C9B0
diff --git a/asm/overlay_29_022F73EC.s b/asm/overlay_29_022F740C.s
similarity index 71%
rename from asm/overlay_29_022F73EC.s
rename to asm/overlay_29_022F740C.s
index 992ab3a4..c1facba1 100644
--- a/asm/overlay_29_022F73EC.s
+++ b/asm/overlay_29_022F740C.s
@@ -1,21 +1,8 @@
 	.include "asm/macros.inc"
-	.include "overlay_29_022F73EC.inc"
+	.include "overlay_29_022F740C.inc"
 
 	.text
 
-	arm_func_start GetKecleonIdToSpawnByFloor
-GetKecleonIdToSpawnByFloor: ; 0x022F73EC
-	stmdb sp!, {r3, lr}
-	bl FloorNumberIsEven
-	cmp r0, #0
-	ldrne r0, _022F7404 ; =0x000003D7
-	ldreq r0, _022F7408 ; =0x0000017F
-	ldmia sp!, {r3, pc}
-	.align 2, 0
-_022F7404: .word 0x000003D7
-_022F7408: .word 0x0000017F
-	arm_func_end GetKecleonIdToSpawnByFloor
-
 	arm_func_start StoreSpriteFileIndexBothGenders
 StoreSpriteFileIndexBothGenders: ; 0x022F740C
 	stmdb sp!, {r3, r4, r5, r6, r7, lr}
@@ -163,46 +150,3 @@ _022F75C8: .word 0x00019914
 _022F75CC: .word ov29_0237C9B0
 _022F75D0: .word WAN_TABLE
 	arm_func_end LoadMonsterSpriteInner
-
-	arm_func_start SwapMonsterWanFileIndex
-SwapMonsterWanFileIndex: ; 0x022F75D4
-	stmdb sp!, {r3, r4, r5, r6, lr}
-	sub sp, sp, #4
-	ldr r2, _022F764C ; =DUNGEON_PTR
-	mov r5, r1
-	ldr r1, [r2]
-	mov r6, r0
-#ifdef JAPAN
-	add r1, r1, #0x870
-	mov r0, r5
-	add r4, r1, #0x19000
-#else
-	add r1, r1, #0x114
-	mov r0, r5
-	add r4, r1, #0x19800
-#endif
-	bl GetSpriteIndex__020526EC
-	mov r1, #1
-	str r1, [sp]
-	mov r1, r6, lsl #1
-	ldr r2, _022F7650 ; =WAN_TABLE
-	mov r3, r0
-	ldrsh r1, [r4, r1]
-	ldr r0, [r2]
-	mov r2, #0
-	bl ReplaceWanFromBinFile
-	mov r1, r0
-	mov r0, r5
-	bl StoreSpriteFileIndexBothGenders
-	mov r3, r6, lsl #1
-	ldrsh r2, [r4, r3]
-	mov r1, r5, lsl #1
-	mov r0, #0
-	strh r2, [r4, r1]
-	strh r0, [r4, r3]
-	add sp, sp, #4
-	ldmia sp!, {r3, r4, r5, r6, pc}
-	.align 2, 0
-_022F764C: .word DUNGEON_PTR
-_022F7650: .word WAN_TABLE
-	arm_func_end SwapMonsterWanFileIndex
diff --git a/include/enums.h b/include/enums.h
index d36c2d12..fba9444b 100644
--- a/include/enums.h
+++ b/include/enums.h
@@ -2913,4 +2913,19 @@ enum mobility_type {
     NUM_MOBILITY_TYPES
 };
 
+enum wan_source_type {
+    WAN_SOURCE_NULL = 0,
+    WAN_SOURCE_FILE = 1, // Directly loaded from a .wan
+    WAN_SOURCE_PACK = 2, // Loaded from a pack file
+};
+
+enum pack_file_id {
+    PACK_ARCHIVE_MONSTER = 0,
+    PACK_ARCHIVE_M_ATTACK = 1,
+    PACK_ARCHIVE_M_GROUND = 2,
+    PACK_ARCHIVE_EFFECT = 3,
+    PACK_ARCHIVE_DUNGEON = 4,
+    PACK_ARCHIVE_M_LEVEL = 5,
+};
+
 #endif //PMDSKY_ENUMS_H
diff --git a/include/overlay_29_022F73B4.h b/include/overlay_29_022F73B4.h
index b47b8313..8387e9da 100644
--- a/include/overlay_29_022F73B4.h
+++ b/include/overlay_29_022F73B4.h
@@ -4,5 +4,6 @@
 #include "util.h"
 
 bool32 FloorNumberIsEven();
+s16 GetKecleonIdToSpawnByFloor();
 
 #endif //PMDSKY_OVERLAY_29_022F73B4_H
diff --git a/include/overlay_29_022F7654.h b/include/overlay_29_022F7654.h
index 90faf2f9..7b90e340 100644
--- a/include/overlay_29_022F7654.h
+++ b/include/overlay_29_022F7654.h
@@ -2,6 +2,7 @@
 #define PMDSKY_OVERLAY_29_022F7654_H
 #include "enums.h"
 
+void SwapMonsterWanFileIndex(s16 src_id, s16 dst_id);
 void LoadMonsterSprite(s16 monster_id, u8 skip_deoxys_check);
 
 #endif //PMDSKY_OVERLAY_29_022F7654_H
diff --git a/include/wan.h b/include/wan.h
index 8f686ddc..14480997 100644
--- a/include/wan.h
+++ b/include/wan.h
@@ -11,4 +11,38 @@ struct wan_animation_frame {
     struct vec2_16 shadow_offset;
 };
 
-#endif //PMDSKY_WAN_H
\ No newline at end of file
+struct wan_table_entry {
+    char path[32];                  // 0x0: Needs to be null-terminated. Only used for direct file.
+    bool8 file_externally_allocated; // 0x20: True if the iov_base shouldn’t be freed by this struct.
+    u8 source_type; // 0x21: 1 = direct file, 2 = pack file
+    s16 pack_id;                      // 0x22: for wan in pack file
+    s16 file_index;                   // 0x24: for wan in pack file
+    u8 field5_0x26;
+    u8 field6_0x27;
+    u32 iov_len;
+    // 0x2C: When removing a reference, if it reaches 0, the entry is removed (unless
+    // file_externally_allocated is true, as it is always removed even if there are remaining
+    // references)
+    s16 reference_counter;
+    u8 field9_0x2e;
+    u8 field10_0x2f;
+    // 0x30: pointer to the beginning of the data section of iov_base.
+    struct wan_header* sprite_start;
+    void* iov_base; // 0x34: points to a sirO
+};
+
+struct wan_table {
+    struct wan_table_entry sprites[96]; // 0x0
+    void* at_decompress_scratch_space;  // 0x1500
+    u8 field2_0x1504;
+    u8 field3_0x1505;
+    u8 field4_0x1506;
+    u8 field5_0x1507;
+    s16 total_nb_of_entries;  // 0x1508: The total number of entries. Should be equal to 0x60.
+    s16 next_alloc_start_pos; // 0x150A
+    s16 field8_0x150c;
+    u8 field9_0x150e;
+    u8 field10_0x150f;
+};
+
+#endif //PMDSKY_WAN_H
diff --git a/main.lsf b/main.lsf
index 8d2806c7..b582ac20 100644
--- a/main.lsf
+++ b/main.lsf
@@ -341,7 +341,7 @@ Overlay OVY_29
 	Object asm/overlay_29_022F62CC.o
 	Object src/overlay_29_022F7364.o
 	Object src/overlay_29_022F73B4.o
-	Object asm/overlay_29_022F73EC.o
+	Object asm/overlay_29_022F740C.o
 	Object src/overlay_29_022F7654.o
 	Object asm/overlay_29_022F7768.o
 	Object src/dungeon_misc.o
diff --git a/src/overlay_29_022F73B4.c b/src/overlay_29_022F73B4.c
index 6da53405..7f62619d 100644
--- a/src/overlay_29_022F73B4.c
+++ b/src/overlay_29_022F73B4.c
@@ -1,11 +1,16 @@
 #include "overlay_29_022F73B4.h"
 #include "dungeon.h"
 #include "util.h"
-
-extern struct dungeon *DUNGEON_PTR[];
+#include "enums.h"
 
 bool32 FloorNumberIsEven() {
     struct dungeon *dungeon = DUNGEON_PTR[0];
     if (dungeon->id == DUNGEON_LABYRINTH_CAVE && dungeon->floor == 10) return 0;
     return (dungeon->floor & 1) == 0;
 }
+
+s16 GetKecleonIdToSpawnByFloor()
+{
+  if (!FloorNumberIsEven()) return MONSTER_KECLEON;
+  else return MONSTER_KECLEON_SECONDARY;
+}
diff --git a/src/overlay_29_022F7654.c b/src/overlay_29_022F7654.c
index dcbd5fc7..5938a57a 100644
--- a/src/overlay_29_022F7654.c
+++ b/src/overlay_29_022F7654.c
@@ -1,7 +1,21 @@
 #include "overlay_29_022F7654.h"
 #include "dungeon.h"
+#include "enums.h"
+#include "wan.h"
+
+extern struct wan_table *WAN_TABLE;
+extern s16 GetSpriteIndex__020526EC(s16 monster_id);
+extern s16 ReplaceWanFromBinFile(struct wan_table *wan_table, s16 wan_id, s16 pack_id, s16 file_index, bool8 compressed);
+extern void StoreSpriteFileIndexBothGenders(s16 monster_id, s16 file_id);
+
+void SwapMonsterWanFileIndex(s16 src_id, s16 dst_id)
+{
+    s16 *sprite_indexes = (s16 *)DUNGEON_PTR[0]->sprite_indexes;
+    StoreSpriteFileIndexBothGenders(dst_id, ReplaceWanFromBinFile(WAN_TABLE, sprite_indexes[src_id], PACK_ARCHIVE_MONSTER, GetSpriteIndex__020526EC(dst_id), TRUE));
+    sprite_indexes[dst_id] = sprite_indexes[src_id];
+    sprite_indexes[src_id] = 0;
+}
 
-extern struct dungeon *DUNGEON_PTR[];
 extern void LoadMonsterSpriteInner(s16 monster_id);
 void LoadMonsterSprite(s16 monster_id, u8 skip_deoxys_check)
 {