Elas il-Kor, Sadistic Pilgrim

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

Soul Warden

Whenever another creature enters, you gain 1 life.

Blood Artist

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

Edgar Markov's Coffin

At the beginning of your upkeep, create a 1/1 white and black Vampire creature token with lifelink and put a bloodline counter on Edgar Markov's Coffin. Then if there are three or more bloodline counters on it, remove those counters and transform it.

Edgar, Charmed Groom

Other Vampires you control get +1/+1.
When Edgar, Charmed Groom dies, return it to the battlefield transformed under its owner's control.

Edgar, Charmed Groom // Edgar Markov's Coffin

Cruel Celebrant

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

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.