Cefira, Silenced Intriguer

Whenever an opponent casts an instant or
sorcery spell, you may play that card from their
graveyard at any time. The number of mana used
to cast that spellis the number of colorless mana
you need to cast it instead. When that instant of
sorcery spell resigns, exile it in its previous
owner's graveyard. When this ability resigns, you
lose 2 life and your opponent gains 1 life.
"You can lose to darkness, or you can be trusted, gain allies, find friends, and overcome it."