Ria, Chaos Caster

{u/r}{u/r},{t}: Exile target instant or sorcery chosen at
random from a graveyard. Until the end step, you
may cast the exiled card without paying its mana
cost. If you cast a spell this
way, it deals damage to you equal to its converted
mana cost. If a card cast this way would be put
into a graveyard this turn, exile it instead.