Dehibilitate

Delve
Each turn, target creature gets X -1/-1 counters,
where X is the number of cards in your graveyard.
Whenever a creature dies this way, exile it and
deal damage to target player or planeswalker equal
to the number of -1/-1 counters it had.
At the beginning of your upkeep, if your
opponents control no creatures, exile
Dehibilitate.