Griztuva, the Cloaked-One

Whenever a nontoken creature dies, put a soul
counter on Griztuva, the Cloaked-One and you
lose 1 life.
{t}, Remove X soul counters from Griztuva, the Cloaked-One and exert it: Return target creature
card with converted mana cost X or less from a graveyard to the battlefield under your control.
That creature gains haste until end of turn. Exile
it at the beginning of the next end step.