Nicol Bolas, The Arisen

+4: You draw 4 cards, you gain 4 life. You may do 10 damage target card, or return target card from a graveyard.
+2: Nicol Bolas, becomes an 8/8 elder dragon with Indestructible, Flying, Haste, Trample, Vigilance, and Deathtouch, who is still a planeswalker.
-14: Target opponent discards half his library, and exiles every other card but one. They also lose half their life, you gain that much life.