Kezi, God Of Dusk And Deep

Indestructible Menace
As long as your devotion to blue and black is less
than seven, Kezi isn't a creature.
During each of your turns, you may play up to
one card of each card type from your graveyard.
{2}{u/b}{u/b} Sacrifice a creature you control
and mill target players library, for the sacrificed
creatures toughness.