diff --git a/include/ability.h b/include/ability.h
index a9bbfdb..071b3ae 100644
--- a/include/ability.h
+++ b/include/ability.h
@@ -5,21 +5,22 @@
 
 #include "assert.h"
 #include "element.h"
+#include "equipment_id.h"
 
 typedef struct {
-    /* 0x00 */ char *name;
-    /* 0x04 */ u8 field_0x4;
-    /* 0x05 */ Element element;
-    /* 0x06 */ u8 field_0x6;
-    /* 0x07 */ u8 field_0x7;
-    /* 0x08 */ u8 field_0x8;
-    /* 0x09 */ u8 field_0x9;
-    /* 0x0a */ u8 field_0xa;
-    /* 0x0b */ u8 field_0xb;
-    /* 0x0c */ u8 field_0xc;
-    /* 0x0d */ u8 field_0xd;
-    /* 0x0e */ u8 field_0xe;
-    /* 0x0f */ u8 field_0xf;
+  /* 0x00 */ char *name;
+  /* 0x04 */ u8 field_0x4;
+  /* 0x05 */ Element element;
+  /* 0x06 */ u8 field_0x6;
+  /* 0x07 */ u8 field_0x7;
+  /* 0x08 */ u8 field_0x8;
+  /* 0x09 */ u8 field_0x9;
+  /* 0x0a */ u8 field_0xa;
+  /* 0x0b */ u8 field_0xb;
+  /* 0x0c */ u8 field_0xc;
+  /* 0x0d */ u8 field_0xd;
+  /* 0x0e */ u8 field_0xe;
+  /* 0x0f */ u8 field_0xf;
 } AbilityData; // size:0x10
 
 ASSERT_SIZE(AbilityData, 0x10);
@@ -28,7 +29,7 @@ extern AbilityData obAbilityData[];
 
 extern char *obAbilityGetName(u8 index);
 extern u8 ability_get_field_0x4(u8 index);
-extern Element obAbilityGetElement(u8 index, u16 arg1, u16 arg2, s32 arg3,
-                                   u16 arg4);
+extern Element obAbilityGetElement(u8 index, EquipmentId arg1, EquipmentId arg2,
+                                   EquipmentId arg3, EquipmentId arg4);
 
 #endif // __ABILITY_H__
\ No newline at end of file
diff --git a/src/segment_obdata/_ob_fierce_selection.c b/src/segment_obdata/_ob_fierce_selection.c
index 2c844a2..655f3ea 100644
--- a/src/segment_obdata/_ob_fierce_selection.c
+++ b/src/segment_obdata/_ob_fierce_selection.c
@@ -277,7 +277,7 @@ u8 ability_get_field_0x4(u8 index) {
 }
 
 /* 44370 8016E470 */
-Element obAbilityGetElement(u8 index, u16 arg1, u16 arg2, s32 arg3, u16 arg4) {
+Element obAbilityGetElement(u8 index, EquipmentId arg1, EquipmentId arg2, EquipmentId arg3, EquipmentId arg4) {
     u16 item_index;    
     
     if (obAbilityData[index].element != ELEMENT_INVALID && obAbilityData[index].element != 0xF)