Karn, Scion of Urza

+1: Reveal top two cards of your library. An opponent chooses one. Put that card into your hand. Exile the other with a silver counter on it.
-1: Put a card you own with a silver counter on it from exile into your hand.
-2: Create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."