Cruel Celebrant

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

Doomed Traveler

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Accursed Marauder

When Accursed Marauder enters, each player sacrifices a nontoken creature of their choice.

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Ministrant of Obligation

Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)