Soulmender

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.)

Purity

Flying
If noncombat damage would be dealt to you, prevent that damage. You gain life equal to the damage prevented this way.
When Purity is put into a graveyard from anywhere, shuffle it into its owner's library.

Celestial Unicorn

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

Nykthos Paragon

Whenever you gain life, you may put that many +1/+1 counters on each creature you control. Do this only once each turn.

Knight of Dawn's Light

First strike
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: This creature gets +1/+1 until end of turn.

Exemplar of Light

Flying
Whenever you gain life, put a +1/+1 counter on this creature.
Whenever you put one or more +1/+1 counters on this creature, draw a card. This ability triggers only once each turn.

Hallow

Prevent all damage target spell would deal this turn. You gain life equal to the damage prevented this way.

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.

Soul's Grace

You gain life equal to target creature's power.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Heron of Hope

Flying
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: This creature gains lifelink until end of turn.

Tenacity

Creatures you control get +1/+1 and gain lifelink until end of turn. Untap those creatures. (Damage dealt by those creatures also causes you to gain that much life.)

Paladin of Atonement

At the beginning of each upkeep, if you lost life last turn, put a +1/+1 counter on this creature.
When this creature dies, you gain life equal to its toughness.

Cat Collector

When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you gain life for the first time during each of your turns, create a 1/1 white Cat creature token.

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.

Boon Reflection

If you would gain life, you gain twice that much life instead.

Leyline of Hope

If this card is in your opening hand, you may begin the game with it on the battlefield.
If you would gain life, you gain that much life plus 1 instead.
As long as you have at least 7 life more than your starting life total, creatures you control get +2/+2.

Path of Bravery

As long as your life total is greater than or equal to your starting life total, creatures you control get +1/+1.
Whenever one or more creatures you control attack, you gain life equal to the number of attacking creatures.

Proper Burial

Whenever a creature you control dies, you gain life equal to that creature's toughness.

Golden Urn

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}, Sacrifice this artifact: You gain life equal to the number of charge counters on this artifact.

Intervention Pact

The next time a source of your choice would deal damage to you this turn, prevent that damage. You gain life equal to the damage prevented this way.
At the beginning of your next upkeep, pay {1}{W}{W}. If you don't, you lose the game.

Rhox Faithmender

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
If you would gain life, you gain twice that much life instead.

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.

Union of the Third Path

Draw a card, then you gain life equal to the number of cards in your hand.

The Gaffer

At the beginning of each end step, if you gained 3 or more life this turn, draw a card.

Ajani's Pridemate

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.

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.

Chant of Vitu-Ghazi

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Prevent all damage that would be dealt by creatures this turn. You gain life equal to the damage prevented this way.

Ajani's Welcome

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

War Report

You gain life equal to the number of creatures on the battlefield plus the number of artifacts on the battlefield.

Gideon's Company

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

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.

Dazzling Reflection

You gain life equal to target creature's power. The next time that creature would deal damage this turn, prevent that damage.

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.

Aetherflux Reservoir

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

Awe Strike

The next time target creature would deal damage this turn, prevent that damage. You gain life equal to the damage prevented this way.

Exile

Exile target nonwhite attacking creature. You gain life equal to its toughness.

Terashi's Grasp

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

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.

Qala, Ajani's Pridemate

Whenever Qala attacks, other attacking creatures you control get +X/+0 until end of turn, where X is the number of counters on Qala.
Whenever you gain life, put a +1/+1 counter on Qala.
{3}{W}: You gain 1 life.

Sunbond

Enchant creature
Enchanted creature has "Whenever you gain life, put that many +1/+1 counters on this creature."

Divine Offering

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

Vanguard Seraph

Flying
Whenever you gain life for the first time each turn, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)