The Promised Tomorrow

Sacrifice a creature, search your gravard for
a card of equal or lesser converted mana cost,
shuffle it into your library and draw a card.
—
"You prayed for Nothing, you want for Nothing,
you gave me much.
Now you ask for Nothing in return? Have no fear,
once Ceto is dead, you can have Nothing;
if you still want it."
Hetatsubachi Una