Number C65: King Overfiend

Card text

3 Level 3 DARK monsters Once per turn: You can detach 1 Xyz Material from this card, then target 1 face-up monster your opponent controls; it loses 1000 ATK and DEF. While this card has "Number 65: Djinn Buster" as an Xyz Material, it gains this effect. ● Effect Monsters your opponent controls cannot activate their effects.