Negative Zone Portal (Surge Foil) [Marvel Super Heroes Commander]

{2}, {T}: Exile target card from an opponent's graveyard. If it's a creature card, draw a card.
At the beginning of your upkeep, if there are four or more creature cards exiled with this artifact, flip a coin. If you lose the flip, sacrifice this artifact and return a card exiled with it at random to its owner's hand.