Lord Viren, Katolis Archmage

{u/r}{b},{t}: Sacrifice a nontoken creature:
Search your library for a noncreature spell
with mana value equal to or less then that
of the sacrificed creature, then exile it. Until
the end of your next turn, you may cast that
spell without paying its mana cost.
Power often comes at a price. For some, though,
no price is too great.