Adds Illuminate's Gen9 effect (#3482)

Co-authored-by: Eduardo Quezada D'Ottone <eduardo602002@gmail.com>

include/config/battle.h

@@ -129,6 +129,7 @@
 #define B_LEAF_GUARD_PREVENTS_REST  GEN_LATEST // In Gen5+, Leaf Guard prevents the use of Rest in harsh sunlight.
 #define B_SNOW_WARNING              GEN_LATEST // In Gen9+, Snow Warning will summon snow instead of hail.
 #define B_TRANSISTOR_BOOST          GEN_LATEST // In Gen9+, Transistor will only boost Electric-type moves by 1.3x as opposed to 1.5x.
+#define B_ILLUMINATE_EFFECT         GEN_LATEST // In Gen9+, Illuminate prevents accuracy reductions and ignores the target's evasion.
 
 // Item settings
 #define B_HP_BERRIES                GEN_LATEST // In Gen4+, berries which restore HP activate immediately after HP drops to half. In Gen3, the effect occurs at the end of the turn.

src/battle_ai_main.c

@@ -869,6 +869,10 @@ static s32 AI_CheckBadMove(u32 battlerAtk, u32 battlerDef, u32 move, s32 score)
                   && move != MOVE_PLAY_NICE && move != MOVE_NOBLE_ROAR && move != MOVE_TEARFUL_LOOK && move != MOVE_VENOM_DRENCH)
                     RETURN_SCORE_MINUS(10);
                 break;
+            case ABILITY_ILLUMINATE:
+                if (B_ILLUMINATE_EFFECT < GEN_9)
+                    break;
+                // fallthrough
             case ABILITY_KEEN_EYE:
                 if (moveEffect == EFFECT_ACCURACY_DOWN || moveEffect == EFFECT_ACCURACY_DOWN_2)
                     RETURN_SCORE_MINUS(10);
@@ -1292,7 +1296,7 @@ static s32 AI_CheckBadMove(u32 battlerAtk, u32 battlerDef, u32 move, s32 score)
         case EFFECT_ACCURACY_DOWN_2:
             if (!ShouldLowerStat(battlerDef, aiData->abilities[battlerDef], STAT_ACC))
                 ADJUST_SCORE(-10);
-            else if (aiData->abilities[battlerDef] == ABILITY_KEEN_EYE)
+            else if (aiData->abilities[battlerDef] == ABILITY_KEEN_EYE || (B_ILLUMINATE_EFFECT >= GEN_9 && aiData->abilities[battlerDef] == ABILITY_ILLUMINATE))
                 ADJUST_SCORE(-8);
             break;
         case EFFECT_EVASION_DOWN:

src/battle_ai_switch_items.c

@@ -347,6 +347,7 @@ static bool8 ShouldSwitchIfGameStatePrompt(u32 battler)
             if (gBattleMons[battler].statStages[STAT_EVASION] > (DEFAULT_STAT_STAGE + 3)
                 && AI_DATA->abilities[opposingBattler] != ABILITY_UNAWARE
                 && AI_DATA->abilities[opposingBattler] != ABILITY_KEEN_EYE
+                && (B_ILLUMINATE_EFFECT >= GEN_9 && AI_DATA->abilities[opposingBattler] != ABILITY_ILLUMINATE)
                 && !(gBattleMons[battler].status2 & STATUS2_FORESIGHT)
                 && !(gStatuses3[battler] & STATUS3_MIRACLE_EYED))
                 switchMon = FALSE;

src/battle_ai_util.c

@@ -1996,6 +1996,7 @@ bool32 ShouldLowerAccuracy(u32 battlerAtk, u32 battlerDef, u32 defAbility)
       && defAbility != ABILITY_WHITE_SMOKE
       && defAbility != ABILITY_FULL_METAL_BODY
       && defAbility != ABILITY_KEEN_EYE
+      && (B_ILLUMINATE_EFFECT >= GEN_9 && defAbility != ABILITY_ILLUMINATE)
       && AI_DATA->holdEffects[battlerDef] != HOLD_EFFECT_CLEAR_AMULET)
         return TRUE;
     return FALSE;

src/battle_script_commands.c

@@ -1623,7 +1623,7 @@ u32 GetTotalAccuracy(u32 battlerAtk, u32 battlerDef, u32 move, u32 atkAbility, u
     gPotentialItemEffectBattler = battlerDef;
     accStage = gBattleMons[battlerAtk].statStages[STAT_ACC];
     evasionStage = gBattleMons[battlerDef].statStages[STAT_EVASION];
-    if (atkAbility == ABILITY_UNAWARE || atkAbility == ABILITY_KEEN_EYE)
+    if (atkAbility == ABILITY_UNAWARE || atkAbility == ABILITY_KEEN_EYE || (B_ILLUMINATE_EFFECT >= GEN_9 && atkAbility == ABILITY_ILLUMINATE))
         evasionStage = DEFAULT_STAT_STAGE;
     if (gBattleMoves[move].ignoresTargetDefenseEvasionStages)
         evasionStage = DEFAULT_STAT_STAGE;
@@ -5058,6 +5058,7 @@ static void Cmd_playstatchangeanimation(void)
                         && ability != ABILITY_FULL_METAL_BODY
                         && ability != ABILITY_WHITE_SMOKE
                         && !(ability == ABILITY_KEEN_EYE && currStat == STAT_ACC)
+                        && !(B_ILLUMINATE_EFFECT >= GEN_9 && ability == ABILITY_ILLUMINATE && currStat == STAT_ACC)
                         && !(ability == ABILITY_HYPER_CUTTER && currStat == STAT_ATK)
                         && !(ability == ABILITY_BIG_PECKS && currStat == STAT_DEF))
                 {
@@ -11437,6 +11438,7 @@ static u32 ChangeStatBuffs(s8 statValue, u32 statId, u32 flags, const u8 *BS_ptr
         }
         else if (!certain
                 && ((battlerAbility == ABILITY_KEEN_EYE && statId == STAT_ACC)
+                || (B_ILLUMINATE_EFFECT >= GEN_9 && battlerAbility == ABILITY_ILLUMINATE && statId == STAT_ACC)
                 || (battlerAbility == ABILITY_HYPER_CUTTER && statId == STAT_ATK)
                 || (battlerAbility == ABILITY_BIG_PECKS && statId == STAT_DEF)))
         {