Karn,Unexpected Visitor

+1: Exile the top 2 cards of your library. You may cast any artifact with a converted mana cost of 2 or less without paying its mana cost
-X: Put target Planeswalker with converted mana cost X or less from your hand onto the battlefield without paying its mana cost
-7: Exile the top 7 cards of your library, then create a token with "Creatures you control get +1/+1 for each of your exiled cards