Exe Dos, the Scourge

+1: Exile the top three cards of your library. Until the end of your turn you may cast up to one non-land card exiled by Exe Dos, the Scourge.
-1: Until your next upkeep, you may cast an instant or sorcery from your graveyard, then exile it.
-6: You may cast any number of cards exiled from the game without paying their mana costs.