The Grim Souleater

Flying, Menace, Deathtouch
On the beginning of your upkeep, create X 2/2 black spirit tokens with flying onto the battlefield, where X is half the number of spirits you control on the battlefield and graveyard added up.
{b}{b}, Pay 2 life: Search your library for a card, revel it, and exile it. As long as it is exiled, you may cast it without paying its mana cost.