Dark Rebellion Cursed Dragon

Pendulum Effect: You can target 2 level 4 “The Phantom Knights” monsters you control; Special Summon this card from your Pendulum Zone, and if you do, attach those monsters to this card as Xyz Materials. You can only use this effect of "Dark Rebellion Cursed Dragon" once per turn.

Monster Effect: 2 Level 4 monsters
If you can Pendulum Summon Level 4, you can Pendulum Summon this face-up card in your Extra Deck. During either player's turn: You can detach 2 Xyz Materials from this card; this card's ATK becomes double its original ATK, then you can halve the ATK of all face-up monsters your opponent controls that were Special Summoned from the Extra Deck. You can only use this effect of "Dark Rebellion Cursed Dragon" once per turn. If this card in the Monster Zone is destroyed by battle or card effect: You can place this card in your Pendulum Zone.