Akali, Rogue Assassin

Ninjutsu {u}{b} ({u}{b}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Akali, Rogue Assassin deals combat damage to a player, exile target creature that player controls until Akali, Rogue Assassin leaves the battlefield. You may cast cards exiled with Akali, Rogue Assassin, and you may spend mana as though it were mana of any color to cast exiled cards.