Initially lock Mini Black Hole item

src/modifier/modifier-type.ts

@@ -10,6 +10,7 @@ import PartyUiHandler, { PokemonMoveSelectFilter, PokemonSelectFilter } from '..
 import * as Utils from '../utils';
 import { TempBattleStat, getTempBattleStatBoosterItemName, getTempBattleStatName } from '../data/temp-battle-stat';
 import { BerryType, getBerryEffectDescription, getBerryName } from '../data/berry';
+import { Unlockables } from '../system/unlockables';
 
 type Modifier = Modifiers.Modifier;
 
@@ -702,7 +703,7 @@ const modifierPool = {
   [ModifierTier.MASTER]: [
     new WeightedModifierType(modifierTypes.MASTER_BALL, 3),
     new WeightedModifierType(modifierTypes.SHINY_CHARM, 2),
-    new WeightedModifierType(modifierTypes.MINI_BLACK_HOLE, 1)
+    new WeightedModifierType(modifierTypes.MINI_BLACK_HOLE, (party: Pokemon[]) => party[0].scene.gameData.unlocks[Unlockables.MINI_BLACK_HOLE] ? 1 : 0)
   ].map(m => { m.setTier(ModifierTier.MASTER); return m; }),
   [ModifierTier.LUXURY]: [
     new WeightedModifierType(modifierTypes.GOLDEN_EXP_CHARM, (party: Pokemon[]) => party.filter(p => p.level < 100).length ? 1 : 0),

src/modifier/modifier.ts

@@ -1010,10 +1010,12 @@ export class HeldItemTransferModifier extends PokemonHeldItemModifier {
   apply(args: any[]): boolean {
     const pokemon = args[0] as Pokemon;
     const targetPokemon = pokemon.isPlayer() ? pokemon.scene.getEnemyPokemon() : pokemon.scene.getPlayerPokemon();
+    if (!targetPokemon)
+      return false;
 
     const transferredModifierTypes: ModifierTypes.ModifierType[] = [];
     const itemModifiers = pokemon.scene.findModifiers(m => m instanceof PokemonHeldItemModifier
-        && (m as PokemonHeldItemModifier).pokemonId === targetPokemon.id, targetPokemon.isPlayer()) as PokemonHeldItemModifier[];
+        && (m as PokemonHeldItemModifier).pokemonId === targetPokemon.id && !m.matchType(this), targetPokemon.isPlayer()) as PokemonHeldItemModifier[];
     
     for (let i = 0; i < this.getStackCount(); i++) {
       if (!itemModifiers.length)