Mortarium, Dreadking

{1}{b}{r}, {t}, discard a card: Destroy target
creature.
{u}{b}, {t}: Target player mills cards until they mill a nonland card.
{u}{b}{r}, {t}: Return a creature from a player's graveyard to the battlefield under your control.
It gains haste until end of turn. Exile it at the beginning of the next end step.