Vaal Hazak, Hellish Fiend

Deathtouch

Whenever Vaal Hazak enters or attacks, put an effluvium counter on target creature you don’t control. (At the beginning of your end step, put a
-1/-1 counter on each creature with an effluvium counter on it.)

Whenever a creature with an effluvium counter on
it dies, put a +1/+1 counter on Vaal Hazak.