Bladebound Tori

First strike, Ninjutsu {1}{b} ( {1}{b}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Bladebound Tori attacks and isn't blocked you may exile a card from your graveyard, if you do Bladebound Tori gets +X/+X until end of turn where X is the number of black mana symbols in that cards mana cost