Hopeful Eidolon

Bestow {3}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Enchanted creature gets +1/+1 and has lifelink.

Authority of the Consuls

Creatures your opponents control enter the battlefield tapped.
Whenever a creature enters the battlefield under an opponent's control, you gain 1 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.)

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.)

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Dawn of Hope

Whenever you gain life, you may pay {2}. If you do, draw a card.
{3}{W}: Create a 1/1 white Soldier creature token with lifelink.

Vampire of the Dire Moon

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Bloodthirsty Aerialist

Flying
Whenever you gain life, put a +1/+1 counter on Bloodthirsty Aerialist.

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.)

Farbog Revenant

Skulk (This creature can't be blocked by creatures with greater power.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Karlov of the Ghost Council

Whenever you gain life, put two +1/+1 counters on Karlov of the Ghost Council.
{W}{B}, Remove six +1/+1 counters from Karlov of the Ghost Council: Exile target creature.

Merciless Eviction

Choose one —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all planeswalkers.

Sunscorch Regent

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Sunscorch Regent and you gain 1 life.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

Odric, Lunarch Marshal

At the beginning of each combat, creatures you control gain first strike until end of turn if a creature you control has first strike. The same is true for flying, deathtouch, double strike, haste, hexproof, indestructible, lifelink, menace, reach, skulk, trample, and vigilance.

Exquisite Blood

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

Ancestor Dragon

Flying
Whenever one or more creatures you control attack, you gain 1 life for each attacking creature.

Obzedat, Ghost Council

When Obzedat, Ghost Council enters the battlefield, target opponent loses 2 life and you gain 2 life.
At the beginning of your end step, you may exile Obzedat. If you do, return it to the battlefield under its owner's control at the beginning of your next upkeep. It gains haste.

Ajani's Welcome

Whenever a creature enters the battlefield under your control, you gain 1 life.

Answered Prayers

Whenever a creature enters the battlefield under your control, you gain 1 life. If Answered Prayers isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Trained Caracal

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

Healer of the Pride

Whenever another creature enters the battlefield under your control, you gain 2 life.

Angel's Feather

Whenever a player casts a white spell, you may gain 1 life.

Angelic Chorus

Whenever a creature enters the battlefield under your control, you gain life equal to its toughness.

Shambling Vent

Shambling Vent enters the battlefield tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Shambling Vent becomes a 2/3 white and black Elemental creature with lifelink until end of turn. It's still a land.

Pristine Talisman

Kraken's Eye

Whenever a player casts a blue spell, you may gain 1 life.

Impassioned Orator

Whenever another creature enters the battlefield under your control, you gain 1 life.

Angel of Vitality

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

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.)

Utter End

Vampire Outcasts

Bloodthirst 2 (If an opponent was dealt damage this turn, this creature enters the battlefield with two +1/+1 counters on it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Evra, Halcyon Witness

Lifelink
{4}: Exchange your life total with Evra, Halcyon Witness's power.

Drana's Emissary

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

Knight of Meadowgrain

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

Healer's Hawk

Angelheart Vial

Whenever you're dealt damage, you may put that many charge counters on Angelheart Vial.
{2}, {T}, Remove four charge counters from Angelheart Vial: You gain 2 life and draw a card.

Soulmender

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Circle of Affliction

As Circle of Affliction enters the battlefield, choose a color.
Whenever a source of the chosen color deals damage to you, you may pay {1}. If you do, target player loses 1 life and you gain 1 life.

Scoured Barrens

Scoured Barrens enters the battlefield tapped.
When Scoured Barrens enters the battlefield, you gain 1 life.
{T}: Add {W} or {B}.

Radiant Fountain

When Radiant Fountain enters the battlefield, you gain 2 life.
{T}: Add {C}.

Brightling

{W}: Brightling gains vigilance until end of turn.
{W}: Brightling gains lifelink until end of turn.
{W}: Return Brightling to its owner's hand.
{1}: Brightling gets +1/-1 or -1/+1 until end of turn.

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 the battlefield tapped.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

Sanguine Bond

Whenever you gain life, target opponent loses that much 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.

Angelic Skirmisher

Flying
At the beginning of each combat, choose first strike, vigilance, or lifelink. Creatures you control gain that ability until end of turn.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Ojutai Exemplars

Whenever you cast a noncreature spell, choose one —
• Tap target creature.
• Ojutai Exemplars gains first strike and lifelink until end of turn.
• Exile Ojutai Exemplars, then return it to the battlefield tapped under its owner's control.

Victory's Herald

Flying
Whenever Victory's Herald attacks, attacking creatures gain flying and lifelink until end of turn.

Dragon's Claw

Whenever a player casts a red spell, you may gain 1 life.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Basilica Screecher

Markov Patrician

Sungrace Pegasus

Flying (This creature can't be blocked except by creatures with flying or reach.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Leonin Elder

Whenever an artifact enters the battlefield, you may gain 1 life.

Debt to the Deathless

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

Fiendslayer Paladin

First strike (This creature deals combat damage before creatures without first strike.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Fiendslayer Paladin can't be the target of black or red spells your opponents control.

Golem's Heart

Whenever a player casts an artifact spell, you may gain 1 life.

Soul Warden

Whenever another creature enters the battlefield, you gain 1 life.

Alabaster Mage

{1}{W}: Target creature you control gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Nip Gwyllion

Kalastria Highborn

Whenever Kalastria Highborn or another Vampire you control dies, you may pay {B}. If you do, target player loses 2 life and you gain 2 life.

Cradle of Vitality

Whenever you gain life, you may pay {1}{W}. If you do, put a +1/+1 counter on target creature for each 1 life you gained.

Suture Priest

Whenever another creature enters the battlefield under your control, you may gain 1 life.
Whenever a creature enters the battlefield under an opponent's control, you may have that player lose 1 life.

Neutralizing Blast

Soul of Theros

Vigilance
{4}{W}{W}: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.
{4}{W}{W}, Exile Soul of Theros from your graveyard: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.

Sorin, Vengeful Bloodlord

As long as it's your turn, creatures and planeswalkers you control have lifelink.
+2: Sorin, Vengeful Bloodlord deals 1 damage to target player or planeswalker.
−X: Return target creature card with mana value X from your graveyard to the battlefield. That creature is a Vampire in addition to its other types.

Nyx-Fleece Ram

At the beginning of your upkeep, you gain 1 life.

Cruel Celebrant

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

Vault Skirge

({B/P} can be paid with either {B} or 2 life.)
Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Dross Harvester

Protection from white
At the beginning of your end step, you lose 4 life.
Whenever a creature dies, you gain 2 life.

Chainer's Torment

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Chainer's Torment deals 2 damage to each opponent and you gain 2 life.
III — Create an X/X black Nightmare Horror creature token, where X is half your life total, rounded up. It deals X damage to you.

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.)

Gonti's Machinations

Whenever you lose life for the first time each turn, you get {E}. (You get an energy counter. Damage causes loss of life.)
Pay {E}{E}, Sacrifice Gonti's Machinations: Each opponent loses 3 life. You gain life equal to the life lost this way.

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and 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.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Soul's Attendant

Whenever another creature enters the battlefield, you may gain 1 life.

Daggerdrome Imp

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

Blood Artist

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

Genju of the Fields

Enchant Plains
{2}: Until end of turn, enchanted Plains becomes a 2/5 white Spirit creature with "Whenever this creature deals damage, its controller gains that much life." It's still a land.
When enchanted Plains is put into a graveyard, you may return Genju of the Fields from your graveyard to your hand.

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.

Wall of Reverence

Defender, flying
At the beginning of your end step, you may gain life equal to the power of target creature you control.

Falkenrath Noble

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

Flensermite

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Gideon's Company

Whenever you gain life, put two +1/+1 counters on Gideon's Company.
{3}{W}: Put a loyalty counter on target Gideon planeswalker.