Crystal Keeper [MP19-EN066] Common

Set: 2019 Gold Sarcophagus Tin Mega Pack Card type: Pendulum/Effect Monster Rarity: Common Attack: 1500 Defense: 1800 If a "Crystal Beast" monster you control battles an opponent's monster, during damage calculation (Quick Effect): You can Tribute this card from your hand or face-up from your field; your battling monster's ATK/DEF become double its original ATK/DEF during that damage calculation only, but it is destroyed at the end of this Damage Step.