Crystilious, Ice God

+2: Sacrifice a creature. When you do, you gain X life and draw X cards, where X is the number of cards in your graveyard and exile.
+4: If your devotion to blue and black is 6 or more, then add five blue and/or black mana on the battlefield.
-11: Destroy everything that all of your opponents have on their battlefields, including their mana. Discard a card.