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.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Sanctum of Stone Fangs

At the beginning of your first main phase, each opponent loses X life and you gain X life, where X is the number of Shrines you control.

Sorin, Ravenous Neonate

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.)
+2: Create a Food token.
−1: Sorin, Ravenous Neonate deals damage equal to the amount of life you gained this turn to any target.
−6: Gain control of target creature. It becomes a Vampire in addition to its other types. Put a lifelink counter on it if you control a white permanent other than that creature or Sorin.

Sorin of House Markov

Lifelink
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.)
At the beginning of each of your postcombat main phases, if you gained 3 or more life this turn, exile Sorin of House Markov, then return him to the battlefield transformed under his owner's control.

Sorin of House Markov // Sorin, Ravenous Neonate

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Pontiff of Blight

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.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Deepwood Legate

If an opponent controls a Forest and you control a Swamp, you may cast this spell without paying its mana cost.
{B}: Deepwood Legate gets +1/+1 until end of turn.

Severed Strands

As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness. Destroy target creature an opponent controls.

Tainted Field

{T}: Add {C}.
{T}: Add {W} or {B}. Activate only if you control a Swamp.

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.)

Crypt Ghast

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.)
Whenever you tap a Swamp for mana, add an additional {B}.

Commissar Severina Raine

Leading from the Front — Whenever Commissar Severina Raine attacks, each opponent loses X life, where X is the number of other attacking creatures.
Summary Execution — {2}, Sacrifice another creature: You gain 2 life and draw a card.

Thrull Parasite

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.)
{T}, Pay 2 life: Remove a counter from target nonland permanent.

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.)

Lunar Convocation

At the beginning of your end step, if you gained life this turn, each opponent loses 1 life.
At the beginning of your end step, if you gained and lost life this turn, create a 1/1 black Bat creature token with flying.
{1}{B}, Pay 2 life: Draw a card.

Treasury Thrull

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.)
Whenever Treasury Thrull attacks, you may return target artifact, creature, or enchantment card from your graveyard to your hand.

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.

Nadier's Nightblade

Whenever a token you control leaves the battlefield, each opponent loses 1 life and you gain 1 life.

Isolated Chapel

Isolated Chapel enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Exsanguinate

Each opponent loses X 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.

Ritual Chamber

When you unlock this door, create a 6/6 black Demon creature token with flying.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life and you gain 2 life. Otherwise, you lose 2 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex // Ritual Chamber

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 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.

Zulaport Cutthroat

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

Debt to the Deathless

Each opponent loses two times X life. You gain life equal to the life lost this way.

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Flay Essence

Exile target creature or planeswalker. You gain life equal to the number of counters on it.

Blind Obedience

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.)
Artifacts and creatures your opponents control enter tapped.

Serene Offering

Destroy target enchantment. You gain life equal to its mana value.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: Nirkana Revenant gets +1/+1 until end of turn.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Cruel Celebrant

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

Life Insurance

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.)
Whenever a nontoken creature dies, you lose 1 life and create a Treasure token.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Dreg Recycler

{T}, Sacrifice an artifact or creature: Each opponent loses 1 life and you gain 1 life.

Lampad of Death's Vigil

{1}, Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.

Knight of Obligation

Vigilance
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.)

Teysa, Opulent Oligarch

Deathtouch
At the beginning of your end step, investigate for each opponent who lost life this turn.
Whenever a Clue you control is put into a graveyard from the battlefield, create a 1/1 white and black Spirit creature token with flying. This ability triggers only once each turn.

Retreat to Hagra

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Scholar of Athreos

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

Acolyte of Aclazotz

{T}, Sacrifice another creature or artifact: Each opponent loses 1 life and you gain 1 life.

Kambal, Profiteering Mayor

Whenever one or more tokens your opponents control enter, for each of them, create a tapped token that's a copy of it. This ability triggers only once each turn.
Whenever one or more tokens you control enter, each opponent loses 1 life and you gain 1 life.

Syndicate Heavy

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.)
At the beginning of each end step, if you gained 4 or more life this turn, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

The Argent Etchings

(As this Saga enters and after your draw step, add a lore counter.)
I — Incubate 2 five times, then transform all Incubator tokens you control.
II — Creatures you control get +1/+1 and gain double strike until end of turn.
III — Destroy all other permanents except for artifacts, lands, and Phyrexians. Exile The Argent Etchings, then return it to the battlefield (front face up).

Elesh Norn

Vigilance
Whenever a source an opponent controls deals damage to you or a permanent you control, that source's controller loses 2 life unless they pay {1}.
{2}{W}, Sacrifice three other creatures: Exile Elesh Norn, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Elesh Norn // The Argent Etchings

Vermin Gorger

{T}, Sacrifice another creature: Each opponent loses 2 life and you gain 2 life.

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.)

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.)

Awakening Hall

When you unlock this door, return all creature cards from your graveyard to the battlefield.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Funeral Room

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Funeral Room // Awakening Hall

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Syndic of Tithes

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Defensive Formation

Rather than the attacking player, you assign the combat damage of each creature attacking you. You can divide that creature's combat damage as you choose among any of the creatures blocking it.

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.)

Bloodthirsty Conqueror

Flying, deathtouch
Whenever an opponent loses life, you gain that much life. (Damage causes loss of life.)

Simulacrum

You gain life equal to the damage dealt to you this turn. Simulacrum deals damage to target creature you control equal to the damage dealt to you this turn.