Servitire, God of Portals

Indestructible, Shadow
As long as you have less than 15 cards in your graveyard, Servitire isn't a creature.
At the beginning of your end step, place a card
from your exile into your graveyard, ignoring any
replacement effects as you do so.
Whenever servitire attacks, cast a card from your
graveyard without paying its mana cost.