Vanishing Vanquisher

Deathtouch
{1}{u/b}: Each player puts the top three cards from their libraries into their graveyards.
{x}{b/g}: Exile up to X cards from any graveyard.
{2}{g/u}{g/u}: Choose target card in exile. If the chosen card is a nonland permanent, return that card to its owner's graveyard, then create a number of 1/1 colorless horrors equal to the converted mana cost of the card. Otherwise you may cast that card for as long as it remains exiled.