Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.