Y'lloh, the Aeon Wurm

Haste, Trample, Menace
Whenever Y'lloh, the Aeon Wurm attacks, exile the top 3 cards of your library facedown and get {e}{e}{e}{e}{e}{e}.
{e}{e}: You may cast target Instant, Sorcery, or Horror Creature exiled by Y'lloh as though it had flash and costs {2}less until end of turn.