Karlov of the Ghost Council

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

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Drana's Emissary

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

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Ascend from Avernus

Return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield. Exile Ascend from Avernus.

Scoured Barrens

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

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.

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.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Guide of Souls

Whenever another creature you control enters, you gain 1 life and get {E} (an energy counter).
Whenever you attack, you may pay {E}{E}{E}. When you do, put two +1/+1 counters and a flying counter on target attacking creature. It becomes an Angel in addition to its other types.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Elenda's Hierophant

Flying
Whenever you gain life, put a +1/+1 counter on this creature.
When this creature dies, create X 1/1 white Vampire creature tokens with lifelink, where X is its power.

Tainted Field

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

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Cathar Commando

Flash
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Shineshadow Snarl

As this land enters, you may reveal a Plains or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {B}.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. This land deals 1 damage to you.

Mortify

Sol Ring

Orzhov Basilica

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Night's Whisper

Retribution of the Ancients

{B}, Remove X +1/+1 counters from among creatures you control: Target creature gets -X/-X until end of turn.

Obscura Storefront

When this land enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you 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.

Soul Warden

Whenever another creature enters, you gain 1 life.

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.

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. This artifact deals 1 damage to you.

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.)

Vault of the Archangel

{T}: Add {C}.
{2}{W}{B}, {T}: Creatures you control gain deathtouch and lifelink until end of turn.

Lurrus of the Dream-Den

Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Lifelink
Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard.

Deathgreeter

Whenever another creature dies, you may gain 1 life.

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.

Essence Channeler

As long as you've lost life this turn, this creature has flying and vigilance.
Whenever you gain life, put a +1/+1 counter on this creature.
When this creature dies, put its counters on target creature you control.

Zulaport Cutthroat

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

Temple of Silence

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {B}.

Amalia Benavides Aguirre

Ward—Pay 3 life.
Whenever you gain life, Amalia Benavides Aguirre explores. Then destroy all other creatures if its power is exactly 20. (To have this creature explore, reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Helping Hand

Return target creature card with mana value 3 or less from your graveyard to the battlefield tapped.

Alseid of Life's Bounty

Lifelink
{1}, Sacrifice this creature: Target creature or enchantment you control gains protection from the color of your choice until end of turn.

Impassioned Orator

Whenever another creature you control enters, you gain 1 life.

Arcane Signet

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Raise the Past

Return all creature cards with mana value 2 or less from your graveyard to the battlefield.

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.

Cruel Celebrant

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

Creeping Bloodsucker

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

Blood Artist

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

Lifecreed Duo

Flying
Whenever another creature you control enters, you gain 1 life.

Orzhov Signet

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.

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice this artifact: Draw a card.

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Hinterland Sanctifier

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Ayli, Eternal Pilgrim

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
{1}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness.
{1}{W}{B}, Sacrifice another creature: Exile target nonland permanent. Activate only if you have at least 10 life more than your starting life total.

Sign in Blood

Target player draws two cards and loses 2 life.

Sorin, Vengeful Bloodlord

During your turn, creatures and planeswalkers you control have lifelink.
+2: Sorin 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.

Leonin Elder

Whenever an artifact enters, you may gain 1 life.

Kambal, Consul of Allocation

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

Despark

Exile target permanent with mana value 4 or greater.

Plains

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

Swamp

Sanguine Bond

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

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Voice of the Blessed

Whenever you gain life, put a +1/+1 counter on this creature.
As long as this creature has four or more +1/+1 counters on it, it has flying and vigilance.
As long as this creature has ten or more +1/+1 counters on it, it has indestructible.

Distinguished Conjurer

Whenever another creature you control enters, you gain 1 life.
{4}{W}, {T}: Exile another target creature you control, then return it to the battlefield under its owner's control.

Godless Shrine

({T}: Add {W} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.