Zkar, Necromaster

Whenever a Creature is put into a graveyard from the battlefield, put a grave counter on Zkar, Necromaster
Remove a grave counter from Zkar, Necromaster: you may cast a creature card from your graveyard(you still must pay the mana cost and any additional costs)
No, I do not believe that it is death, but it is undeath, unnatural resurrection