Fell Teller

At the end of combat on each player's turn, for each creature that player controls whose power is less than 0, that player may pay {1}. If that player does, that player manifests a card at random from their graveyard. (That player puts it on the battlefield face down as a 2/2 creature and can turn it face up at any time for its mana cost if its a creature card.)
Face down creatures have skulk. (They cannot be blocked by creatures with greater power.)