Witch Hunt

Whenever a creature attacks one of your opponents or a planeswalker an opponent controls, that creature gets +2/+0 until end of turn.

Whenever this creature blocks, exchange its power and the power of target creature it's blocking until end of combat.

Death Grasp deals X damage to any target. You gain X life.

At the beginning of each end step, each player gains control of all nontoken permanents they own.