From 64c2eb39c0f65632ed06b1b19bbf2fca4dc7b089 Mon Sep 17 00:00:00 2001
From: Ultimate Bob <ultimate.bob808@gmail.com>
Date: Tue, 9 May 2023 02:33:12 +1000
Subject: [PATCH] Ignore Illusion if the pokemon is the last slot in the party.

---
 src/battle_util.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/battle_util.c b/src/battle_util.c
index cd65d58093..dd6e2bc06e 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -10398,12 +10398,19 @@ bool32 SetIllusionMon(struct Pokemon *mon, u32 battlerId)
 {
     struct Pokemon *party, *partnerMon;
     s32 i, id;
+    u8 side, partyCount;
 
     gBattleStruct->illusion[battlerId].set = 1;
     if (GetMonAbility(mon) != ABILITY_ILLUSION)
         return FALSE;
 
     party = GetBattlerParty(battlerId);
+    side = GetBattlerSide(battlerId);
+    partyCount = side == B_SIDE_PLAYER ? gPlayerPartyCount : gEnemyPartyCount;
+
+    // If this pokemon is last in the party, ignore Illusion.
+    if (&party[partyCount - 1] == mon)
+        return FALSE;
 
     if (IsBattlerAlive(BATTLE_PARTNER(battlerId)))
         partnerMon = &party[gBattlerPartyIndexes[BATTLE_PARTNER(battlerId)]];