Curse Warden

{w}{b}: Target opponent may put two -1/-1 counters on target creature they control. It they do not, destroy target artifact or enchantment.
{w}{b}{b}: Target opponent may put two -1/-1 counters on target creature they control. If they do not, put three -1/-1 counters on another target creature that dealt damage this turn.
The key to defeating a more formidable enemy is never letting them reach the gates.