Number C9: Chaos Dyson Sphere (PGLD-EN022) [Premium Gold]

3 Level 10 monsters
At the start of the Damage Step, if this card battles an opponent's monster: You can attach that monster to this card as a face-up Xyz Material. Once per turn: You can inflict 300 damage to your opponent for each Xyz Material attached to this card. If this card has "Number 9: Dyson Sphere" as an Xyz Material, it gains this effect.
? Once per turn: You can detach any number of Xyz Materials from this card; inflict 800 damage to your opponent for each Xyz Material detached.