Mitchell, Lord of Ravnica

+2: Scry 2, then reveal the top card of your library. You gain life equal to its casting cost.
-4: Exile the top six cards of your library. Until the end of your next turn, you may cast them without paying their mana cost.
-12: Look at the top ten cards of your library. You may cast any number of them without paying their mana costs. Double your life total.