Corpse Knight

Whenever another creature you control enters, each opponent loses 1 life.

Cruel Celebrant

Whenever Cruel Celebrant or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Liesa, Shroud of Dusk

Rather than pay {2} for each previous time you've cast this spell from the command zone this game, pay 2 life that many times.
Flying, lifelink
Whenever a player casts a spell, they lose 2 life.

Conjurer's Ban

Choose a card name. Until your next turn, spells with the chosen name can't be cast and lands with the chosen name can't be played.
Draw a card.

Castigate

Target opponent reveals their hand. You choose a nonland card from it and exile that card.