Skull of the Betrothed

{t}, Sacrifice a nontoken creature: Put an Oath
counter on Skull of the Betrothed. Search your
library for a creature card with converted mana
cost equal to the sacrificed creature's power
plus 1 and put it in your hand.
Remove 6 Oath Counters from Skull of the
Betrothed: You may put a Demon from your
hand on to the battlefield. Activate this only
as a Sorcery.