Syndicate Enforcer

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Soul Warden

Whenever another creature enters, you gain 1 life.

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

Siege Zombie

Tap three untapped creatures you control: Each opponent loses 1 life.

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Blood Seeker

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

Giant's Skewer

Equipped creature gets +2/+1.
Whenever equipped creature deals combat damage to a creature, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.

Gruesome Fate

Each opponent loses 1 life for each creature you control.

Bake into a Pie

Destroy target creature. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Syndic of Tithes

Kingpin's Pet

Flying
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Basilica Screecher

Servant of Tymaret

Inspired — Whenever Servant of Tymaret becomes untapped, each opponent loses 1 life. You gain life equal to the life lost this way.
{2}{B}: Regenerate Servant of Tymaret.

Tyrant's Choice

Will of the council — Starting with you, each player votes for death or torture. If death gets more votes, each opponent sacrifices a creature of their choice. If torture gets more votes or the vote is tied, each opponent loses 4 life.

Silverquill Pledgemage

Magecraft — Whenever you cast or copy an instant or sorcery spell, Silverquill Pledgemage gains your choice of flying or lifelink until end of turn.

Tithe Drinker

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Foreboding Fruit

Target player draws two cards and loses 2 life.
Adamant — If at least three black mana was spent to cast this spell, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Basilica Guards

Defender
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Indulging Patrician

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your end step, if you gained 3 or more life this turn, each opponent loses 3 life.

Late to Dinner

Return target creature card from your graveyard to the battlefield. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Marauding Blight-Priest

Scholar of Athreos

{2}{B}: Each opponent loses 1 life. You gain life equal to the life lost this way.

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.

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.