Azrael, Ever-Consuming

Flying, Devour X, where X is the number of creatures you sacrifice to activate this ability.

Azrael, Ever-Consuming cannot attack or block unless there are 8 or more creature cards in your graveyard.

You may cast creature spells from your graveyard. As an additional cost to cast creature spells from your graveyard, sacrifice a creature. The mana cost of that spell is reduced by the converted mana cost of the sacrificed creature.