Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Kalain, Reclusive Painter

When Kalain, Reclusive Painter enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Other creatures you control enter with an additional +1/+1 counter on them for each mana from a Treasure spent to cast them.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.