Niv-Mizzet awakened

: Knowledge (Exile any number of Instant and Sorcery cards from your Graveyard while casting this spell. Each card exiled this way pays for 1.)
+1: Draw a card. Exile the top card of your Library: if it's and Instant or Sorcery card, inflict 1 damage to any target.
-X: Exile Niv-Mizzet awakened. You can cast up to X Instant and Sorcery cards from your exile without paying their mana costs