Throne of the Eternal Slumber

Imprint - As you cast this card, look at the top 5
cards of your library. From among the cards in
your hand and the top 5 cards, exile one
face-down. Shuffle your library.
{t}, Sacrifice Throne of the Eternal Slumber,
Sacrifice target creature: Cast the card exiled with
Throne of the Eternal Slumber, it's mana cost is reduced by X, where X is the converted mana
cost of the sacrificed creature.