Bloodhunter Bat

Flying
When Bloodhunter Bat enters, target player loses 2 life and you gain 2 life.

Moonrise Cleric

Flying
Whenever Moonrise Cleric attacks, you gain 1 life.

Orzhov Signet

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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Wax-Wane Witness

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

Rodolf Duskbringer

Flying, deathtouch, lifelink
Whenever you gain life, Rodolf Duskbringer gains indestructible until end of turn.
At the beginning of your end step, you may pay {1}{W/B}. When you do, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Starlit Soothsayer

Flying
At the beginning of your end step, if you gained or lost life this turn, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Moonstone Harbinger

Flying, deathtouch
Whenever you gain or lose life during your turn, Bats you control get +1/+0 and gain deathtouch until end of turn. This ability triggers only once each turn.

Bloodthirsty Aerialist

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

Season of the Burrow

Choose up to five {P} worth of modes. You may choose the same mode more than once.
{P} — Create a 1/1 white Rabbit creature token.
{P}{P} — Exile target nonland permanent. Its controller draws a card.
{P}{P}{P} — Return target permanent card with mana value 3 or less from your graveyard to the battlefield with an indestructible counter on it.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Sol Ring

Plains

Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Lifecreed Duo

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

Glidedive Duo

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

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on Wall of Limbs.
{5}{B}{B}, Sacrifice Wall of Limbs: Target player loses X life, where X is Wall of Limbs's power.

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.

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.

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.

Terramorphic Expanse

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

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.

Courier Bat

Flying
When Courier Bat enters, if you gained life this turn, return up to one target creature card from your graveyard to your hand.

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.

Darkstar Augur

Offspring {B} (You may pay an additional {B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Malakir Familiar

Flying, deathtouch
Whenever you gain life, Malakir Familiar gets +1/+1 until end of turn.

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.)

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. Talisman of Hierarchy deals 1 damage to you.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Essence Channeler

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

Shattered Sanctum

Shattered Sanctum enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Voice of the Blessed

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

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.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

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.)

Evolving Wilds

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

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Zoraline, Cosmos Caller

Flying, vigilance
Whenever a Bat you control attacks, you gain 1 life.
Whenever Zoraline enters or attacks, you may pay {W}{B} and 2 life. When you do, return target nonland permanent card with mana value 3 or less from your graveyard to the battlefield with a finality counter on it.

Veinwitch Coven

Menace
Whenever you gain life, you may pay {B}. If you do, return target creature card from your graveyard to your hand.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Star Charter

Flying
At the beginning of your end step, if you gained or lost life this turn, look at the top four cards of your library. You may reveal a creature card with power 3 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Twinblade Paladin

Whenever you gain life, put a +1/+1 counter on this creature.
As long as you have 25 or more life, this creature has double strike. (It deals both first-strike and regular combat damage.)

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Swamp

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.

Command Tower

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

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.)

Starseer Mentor

Flying, vigilance
At the beginning of your end step, if you gained or lost life this turn, target opponent loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.

Blind Hunter

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When Blind Hunter enters or the creature it haunts dies, target player loses 2 life and you gain 2 life.

Moonstone Eulogist

Flying
Whenever a creature an opponent controls dies, you create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on Moonstone Eulogist and you gain 1 life.

Ajani's Pridemate

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

Arcane Signet

Isolated Chapel

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

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

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.)

Heliod, Sun-Crowned

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
Whenever you gain life, put a +1/+1 counter on target creature or enchantment you control.
{1}{W}: Another target creature gains lifelink until end of turn.