Psyche, Wretched Wanderer

First strike, Wither (This deals damage to
creatures in the form of -1/-1 counters.)
Whenever a creature is put into exile from the battlefield, Psyche, Wretched Wanderer deals
damage equal to his power to target opponent
If a creature dealt damage by Psyche, Wretched Wanderer would die this turn, exile that creature instead.