Ervali, Starving Shadow

Flying, indestructible
Instants and sorceries you control cost {1} less for each +1/+1 counter on Ervali.
Hound of Ill Omen - {x}{b}{b}: Create an X/X black Demon Wolf creature token called Rufus with "Whenever a creature dealt combat damage by Rufus dies this turn, put a +1/+1 counter on Ervali, Starving Shadow." That token then fights target creature.