Bolas's Reaver

Whenever a creature deals damage to an opponent, they discard a card.
As long as you control a Nichol Bolas Planeswalker Card, this card gets +1/+1, Menace, and "Whenever an opponent discards a card, they discar an additional card.
"The last Thing we need is a second Bolas running around. Of course he didn't grant our wish," -Ajani