George, Berserk Healer

+2: Reveal a card, add 1 mana to your mana pool for each of its colours, then exile it. The number of cards exiled in this way is recorded as X
-2: Return target creature exiled by George, Berserk Healer to the battlefield under your control.
-11: Draw a card. If it is white, gain X life. If it is black, exile X number of target creatures. If it is red, deal X damage to all opponents.