Dark Armed, the Dragon of Annihilation

2+ Level 7 monsters
Once per turn, if you have exactly 5 DARK monsters in your GY, you can also Xyz Summon "Dark Armed, the Dragon of Annihilation" by using 1 Level 5 or higher DARK Dragon monster you control as material. You can detach 1 material from this card, then target 1 card your opponent controls; destroy it, then banish 1 card from your GY, also, this card cannot attack for the rest of this turn.