Erasmus, Keeper of Power

+2: Return a creature card with converted mana cost 3 or less from your graveyard to the battlefield. You lose life equal to the
-3: Destroy target creature. Gain life equal to its toughness. If the destroyed creature was an opponent's, draw a card.
-7: Destroy X creatures and return X creatures under your control where X is equal to the life difference between you and your opponent.