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.)

Bonecache Overseer

{T}, Pay 1 life: Draw a card. Activate only if three or more cards left your graveyard this turn or if you've sacrificed a Food this turn.

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.)

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.)

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}.

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.

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Soul-Shackled Zombie

When this creature enters, exile up to two target cards from a single graveyard. If at least one creature card was exiled this way, each opponent loses 2 life and you gain 2 life.

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.

Cathar Commando

Flash (You may cast this spell any time you could cast an instant.)
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Syndic of Tithes

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.)

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Disfigure

Target creature gets -2/-2 until end of turn.

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.")

Scoured Barrens

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {B}.

Angel of Vitality

Flying
If you would gain life, you gain that much life plus 1 instead.
This creature gets +2/+2 as long as you have 25 or more life.

Vizkopa Confessor

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.)
When Vizkopa Confessor enters, pay any amount of life. Target opponent reveals that many cards from their hand. You choose one of them and exile it.

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.

Stonehorn Dignitary

When Stonehorn Dignitary enters, target opponent skips their next combat phase.

Alchemist's Gift

Target creature gets +1/+1 and gains your choice of deathtouch or lifelink until end of turn. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it. Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Vizkopa Guildmage

{1}{W}{B}: Target creature gains lifelink until end of turn.
{1}{W}{B}: Whenever you gain life this turn, each opponent loses that much life.

Wax-Wane Witness

Flying, vigilance
Whenever you gain or lose life during your turn, Wax-Wane Witness gets +1/+0 until end of turn.

Orzhov Guildgate

This land enters tapped.
{T}: Add {W} or {B}.

Taste of Blood

Taste of Blood deals 1 damage to target player or planeswalker and you gain 1 life.

Tormented Soul

Tormented Soul can't block and can't be blocked.

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.

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

Drana's Emissary

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

Duskhunter Bat

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Flying

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Basilica Screecher

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.)

Stab

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.)

Exquisite Blood

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

Sanguine Bond

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

Lazotep Reaver

When Lazotep Reaver enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Attended Healer

Whenever you gain life for the first time each turn, create a 1/1 white Cat creature token.
{2}{W}: Another target Cleric gains lifelink until end of turn.

Starscape Cleric

Offspring {2}{B} (You may pay an additional {2}{B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
This creature can't block.
Whenever you gain life, each opponent loses 1 life.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Kingpin's Pet

Syndicate Enforcer

Make Your Move

Destroy target artifact, enchantment, or creature with power 4 or greater.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Cleric of Life's Bond

Whenever another Cleric you control enters, you gain 1 life.
Whenever you gain life for the first time each turn, put a +1/+1 counter on Cleric of Life's Bond.

Glidedive Duo

Flying
When Glidedive Duo enters, each opponent loses 2 life and you gain 2 life.

Stromkirk Bloodthief

At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on target Vampire you control.