Scourge of the Void

Intimidate, Flying
Whenever Scourge of the Void deals combat damage to a creature an opponent controls, put a -1/-1 counter on that creature.
At the beginning of your upkeep, you may select an opponent. If you do, Scourge of the Void can only attack that opponent this turn, but gets +1/+1 for each -1/-1 counter on creatures that opponent controls.