Soulwarden of Nyx

When Soulwarden of Nyx enters the battlefield, exile a creature card with converted mana cost 3 or less from your graveyard.
{1}{w}{u}, Sacrifice Soulwarden of Nyx: Reveal the top card of your library. If it's a creature card that shares a creature type with the exiled card, you may cast the exiled card without paying its mana cost. Then shuffle your library. If you didn't cast the exiled card, draw a card.