2 Level 9 monsters While this card has Xyz Material, negate the effects of all monsters your opponent controls without a Level. Once per turn, during either player's turn, if your opponent activates a monster effect: You can detach 1 Xyz Material from this card; negate that effect, halve its ATK and DEF, and if you do, inflict damage to your opponent equal to its lost ATK or DEF (whichever is higher. Your choice, if tied). During your Standby Phase, if this card has no Xyz Materials attached to it: You can target 2 monsters in your Graveyard; attach those targets to this card as Xyz Materials, and if you do, destroy 1 monster your opponent controls. You can only use this effect of "Death Star" once per Duel.