Karn, Mirrodin's Savior

+4: Target creature you control gains hexproof and indestructible until your next turn. Remove up to one poison counter from target player.
-4: Gain control of target creature. If it has infect, it loses infect. You gain life equal to that creature's toughness.
-20: Gain control of target player during their next two turns. Gain control of all permanents played during those turns.