All-Eyes Phantom Dragon [BLHR-EN043] Secret Rare

Pendulum Effect : Once per turn, at the end of the Damage Step, if your Dragon Pendulum Monster attacked an opponent's monster: You can activate this effect; it can attack again in a row. You cannot declare attacks the turn you activate this effect, except with that monster.
Monster Effect : Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand or face-up Extra Deck) by Tributing all monsters you control (min. 2), including a Dragon Pendulum Monster. You can only Special Summon "All-Eyes Phantom Dragon" once per turn this way. Once per turn, during damage calculation, if this card battles an opponent's monster: Double this card's current ATK until the end of this turn. Once per turn, when your opponent activates a Spell/Trap Card or effect (Quick Effect): You can send 1 Spell/Trap you control to the GY; negate the activation.