Xyto, Protector of Skies

Defender, Flying, Wither (This creature deals damage in form of -1/-1 counters.)

Whenever Uthali, Peacekeeper leaves play, exile Xyto, Protector of Skies.
Sacrifice Xyto, Protector of Skies, Target Uthali, Peacekeeper cannot leave the battlefield this turn.