2 Level 9 monsters
Once per Battle Step, during your opponent's turn, if this card with Xyz Material is attacked: Negate the attack (this is a Quick Effect). When this card is targeted for an attack while it has no Xyz Materials. You can target 2 monsters in your Graveyard; attach those targets to this card as Xyz Materials. During your Main Phase 1: You can detach 1 Xyz Material from this card; this card can attack your opponent directly this turn. Your opponent must control a monster with higher ATK than this card for you to activate and to resolve this effect.