Aborruk, Cunning Atrocity

When Aborruk, Cunning Atrocity enters the battlefield, choose a creature you control and a creature you don't control. Aborruk's power is equal to the toughness of one of these creatures and its toughness is equal to the other creature's power.
Whenever you discard two or more cards, draw a card. Then Aborruk deals 1 damage to each opponent.