Grand Chancellor Abnur Tharn

When Grand Chancellor Abnur Tharn enters
the battlefield, exile up to one target sorcery card
from a graveyard. You may copy that card, and
you may cast the copy without paying its mana
cost. If you don't copy that card, the next Daedra
spell you cast this turn costs {x} less to cast, where
X is equal to the exiled card's mana value.
{2}{u/b}, {t}, Discard a card: Tap target creature.