Valkyrie Harbinger

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of each end step, if you gained 4 or more life this turn, create a 4/4 white Angel creature token with flying and vigilance.

Sunscorch Regent

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

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Cultivate

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.

Ajani's Welcome

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

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

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.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Selvala, Explorer Returned

Parley — {T}: Each player reveals the top card of their library. For each nonland card revealed this way, add {G} and you gain 1 life. Then each player draws a card.

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.

Felidar Sovereign

Vigilance (Attacking doesn't cause this creature to tap.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your upkeep, if you have 40 or more life, you win the game.

Swords to Plowshares

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

Impassioned Orator

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

Angel of Destiny

Flying, double strike
Whenever a creature you control deals combat damage to a player, you and that player each gain that much life.
At the beginning of your end step, if you have at least 15 life more than your starting life total, each player Angel of Destiny attacked this turn loses the game.

Ezzaroot Channeler

Reach
Creature spells you cast cost {X} less to cast, where X is the amount of life you gained this turn.
{T}: You gain 2 life.

Archangel of Thune

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, put a +1/+1 counter on each creature you control.

Authority of the Consuls

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

Accomplished Alchemist

{T}: Add one mana of any color.
{T}: Add X mana of any one color, where X is the amount of life you gained this turn.

Soul Warden

Whenever another creature enters, you gain 1 life.

Sol Ring

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.

Beast Within

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

Command Tower

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

Griffin Aerie

At the beginning of your end step, if you gained 3 or more life this turn, create a 2/2 white Griffin creature token with flying.

Blossoming Bogbeast

Whenever Blossoming Bogbeast attacks, you gain 2 life. Then creatures you control gain trample and get +X/+X until end of turn, where X is the amount of life you gained this turn.

Trelasarra, Moon Dancer

Whenever you gain life, put a +1/+1 counter on Trelasarra, Moon Dancer and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Beacon of Immortality

Double target player's life total. Shuffle Beacon of Immortality into its owner's library.

Angelic Accord

At the beginning of each end step, if you gained 4 or more life this turn, create a 4/4 white Angel creature token with flying.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Serra Avatar

Serra Avatar's power and toughness are each equal to your life total.
When Serra Avatar is put into a graveyard from anywhere, shuffle it into its owner's library.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Speaker of the Heavens

Vigilance, lifelink (Attacking doesn't cause this creature to tap. Damage dealt by this creature also causes you to gain that much life.)
{T}: Create a 4/4 white Angel creature token with flying. Activate only if you have at least 7 life more than your starting life total and only as a sorcery.

Ajani, the Greathearted

Creatures you control have vigilance.
+1: You gain 3 life.
−2: Put a +1/+1 counter on each creature you control and a loyalty counter on each other planeswalker you control.

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.