Have

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.

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Selesnya Sanctuary

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

Aerith Gainsborough

Lifelink
Whenever you gain life, put a +1/+1 counter on Aerith Gainsborough.
When Aerith Gainsborough dies, put X +1/+1 counters on each legendary creature you control, where X is the number of +1/+1 counters on Aerith Gainsborough.

Abzan Battle Priest

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has lifelink.

Authority of the Consuls

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

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.

Prize Pig

Whenever you gain life, put that many ribbon counters on this creature. Then if there are three or more ribbon counters on this creature, remove those counters and untap it.
{T}: Add one mana of any color.

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.

Overgrown Farmland

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Nyx-Fleece Ram

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

Archdruid's Charm

Choose one —
• Search your library for a creature or land card and reveal it. Put it onto the battlefield tapped if it's a land card. Otherwise, put it into your hand. Then shuffle.
• Put a +1/+1 counter on target creature you control. It deals damage equal to its power to target creature you don't control.
• Exile target artifact or enchantment.

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.

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.

Lifecreed Duo

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

Prosperous Innkeeper

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever another creature you control enters, you gain 1 life.

Plains

Lightning Greaves

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

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.

The Wind Crystal

White spells you cast cost {1} less to cast.
If you would gain life, you gain twice that much life instead.
{4}{W}{W}, {T}: Creatures you control gain flying and lifelink until end of turn.

Ancient Cornucopia

Whenever you cast a spell that's one or more colors, you may gain 1 life for each of that spell's colors. Do this only once each turn.
{T}: Add one mana of any color.

Sunpetal Grove

This land enters tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Ajani's Welcome

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

The Earth Crystal

Green spells you cast cost {1} less to cast.
If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.
{4}{G}{G}, {T}: Distribute two +1/+1 counters among one or two target creatures you control.

Spike Feeder

This creature enters with two +1/+1 counters on it.
{2}, Remove a +1/+1 counter from this creature: Put a +1/+1 counter on target creature.
Remove a +1/+1 counter from this creature: You gain 2 life.

Adventurer's Inn

When this land enters, you gain 2 life.
{T}: Add {C}.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

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.

Swords to Plowshares

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

Fortified Village

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

Radiant Fountain

Talisman of Unity

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

Graypelt Refuge

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

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Metropolis Reformer

Flying, vigilance
You have hexproof.
Whenever this creature is dealt damage, you gain that much life.

Tuskguard Captain

Outlast {G} ({G}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has trample.

Envoy of the Ancestors

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Modified creatures you control have lifelink. (Equipment, Auras you control, and counters are modifications.)

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.

Sunbond

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

Trelasarra, Moon Dancer

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

Brushland

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

Mangara, the Diplomat

Lifelink
Whenever an opponent attacks with creatures, if two or more of those creatures are attacking you and/or planeswalkers you control, draw a card.
Whenever an opponent casts their second spell each turn, draw a card.

Hinterland Sanctifier

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

Pristine Talisman

Light of Promise

Ajani's Pridemate

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

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.

Walking Ballista

This creature enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on this creature.
Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

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.)

Vexilus Praetor

Flash
Vigilance
Aegis of the Emperor — Commanders you control have protection from everything.

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Ajani, Mentor of Heroes

+1: Distribute three +1/+1 counters among one, two, or three target creatures you control.
+1: Look at the top four cards of your library. You may reveal an Aura, creature, or planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
−8: You gain 100 life.

Boon Reflection

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

Exotic Orchard

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

Sol Ring

Beast Within

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

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, this creature gets +5/+5 and has flying.

Temple of Plenty

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 {G} or {W}.

Essence Warden

Whenever another creature enters, you gain 1 life.

Forest

Command Tower

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

Abzan Falconer

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has flying.

Excalibur II

Whenever you gain life, put a charge counter on Excalibur II.
Equipped creature gets +1/+1 for each charge counter on Excalibur II.
Equip {3}

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.

Honor Troll

Vigilance
If you would gain life, you gain that much life plus 1 instead.
This creature gets +2/+1 as long as you have 25 or more life.

Fountain of Renewal

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

Treebeard, Gracious Host

Trample, ward {2}
When Treebeard enters, create two Food tokens.
Whenever you gain life, put that many +1/+1 counters on target Halfling or Treefolk.

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

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.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Ajani, Strength of the Pride

+1: You gain life equal to the number of creatures you control plus the number of planeswalkers you control.
−2: Create a 2/2 white Cat Soldier creature token named Ajani's Pridemate with "Whenever you gain life, put a +1/+1 counter on this token."
0: If you have at least 15 life more than your starting life total, exile Ajani and each artifact and creature your opponents control.

Arcane Signet

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from each color until end of turn.

Sungrass Prairie

Conclave Mentor

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on that creature instead.
When this creature dies, you gain life equal to its power.

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.

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is this creature's power.

Cosmos Elixir

At the beginning of your end step, draw a card if your life total is greater than your starting life total. Otherwise, you gain 2 life.