GTC: Immortal Servitude, Sorcery X(W/B)(W/B)(W/B) Return each creature card with converted mana cost X from your graveyard to the battlefield.

Immortal Servitude

Return each creature card with converted mana cost X from your graveyard to the battlefield.

1/24/2013 If a creature card in a graveyard has X in its mana cost, that X is considered to be 0.