Paladin of Atonement

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

Knight of Dawn's Light

First strike
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: Knight of Dawn's Light gets +1/+1 until end of turn.

Ondu Cleric

Whenever Ondu Cleric or another Ally you control enters, you may gain life equal to the number of Allies you control.

Prize Pig

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

Gideon's Company

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

Borderland Explorer

When Borderland Explorer enters, each player may discard a card. Each player who discarded a card this way may search their library for a basic land card, reveal it, put it into their hand, then shuffle.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Boulderbranch Golem

Prototype {3}{G} — 3/3 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
When Boulderbranch Golem enters, you gain life equal to its power.

Revered Unicorn

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Revered Unicorn leaves the battlefield, you gain life equal to the number of age counters on it.

Bushwhack

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Boon Reflection

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

Elspeth Tirel

+2: You gain 1 life for each creature you control.
−2: Create three 1/1 white Soldier creature tokens.
−5: Destroy all other permanents except for lands and tokens.

Blighted Woodland

{T}: Add {C}.
{3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Setessan Petitioner

When Setessan Petitioner enters, you gain life equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Hallow

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

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.

Borderland Ranger

When Borderland Ranger enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Conservatory

Conservatory enters tapped.
{T}: Add {G} or {W}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

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.

Command Tower

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

Exile

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

Heal the Scars

Regenerate target creature. You gain life equal to that creature's toughness.

Ageless Entity

Whenever you gain life, put that many +1/+1 counters on Ageless Entity.

Forest

Invigorating Falls

You gain life equal to the number of creature cards in all graveyards.

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.

Gristleback

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Sacrifice Gristleback: You gain life equal to Gristleback's power.

Nylea's Disciple

When Nylea's Disciple enters, you gain life equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Predator's Rapport

Choose target creature you control. You gain life equal to that creature's power plus its toughness.

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.

Nissa's Revelation

Scry 5, then reveal the top card of your library. If it's a creature card, you draw cards equal to its power and you gain life equal to its toughness.

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.

Bretagard Stronghold

Bretagard Stronghold enters tapped.
{T}: Add {G}.
{G}{W}{W}, {T}, Sacrifice Bretagard Stronghold: Put a +1/+1 counter on each of up to two target creatures you control. They gain vigilance and lifelink until end of turn. Activate only as a sorcery.

Lagonna-Band Storyteller

When Lagonna-Band Storyteller enters, you may put target enchantment card from your graveyard on top of your library. If you do, you gain life equal to its mana value.

Plains

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 Ajani's Pridemate."
0: If you have at least 15 life more than your starting life total, exile Ajani, Strength of the Pride and each artifact and creature your opponents control.

Ajani's Pridemate

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

Gourmand's Talent

(Gain the next level as a sorcery to add its ability.)
During your turn, artifacts you control are Foods in addition to their other types and have "{2}, {T}, Sacrifice this artifact: You gain 3 life."
{2}{G}: Level 2
Whenever you gain life for the first time each turn, create a 3/3 green Raccoon creature token.
{3}{G}: Level 3
Whenever you gain life for the first time each turn, put a +1/+1 counter on each creature you control.

Arctic Flats

Arctic Flats enters tapped.
{T}: Add {G} or {W}.

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.

Animal Boneyard

Enchant land
Enchanted land has "{T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness."

Angelic Chorus

Whenever a creature you control enters, you gain life equal to its toughness.

Chastise

Destroy target attacking creature. You gain life equal to its power.

Sheltering Word

Target creature you control gains hexproof until end of turn. You gain life equal to that creature's toughness. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Momentous Fall

As an additional cost to cast this spell, sacrifice a creature.
You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

Sol Ring

Beneath the Sands

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

Blossoming Wreath

You gain life equal to the number of creature cards in your graveyard.

Dazzling Reflection

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

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.

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.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

Blossoming Sands

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

Idyllic Grange

({T}: Add {W}.)
Idyllic Grange enters tapped unless you control three or more other Plains.
When Idyllic Grange enters untapped, put a +1/+1 counter on target creature you control.

Serene Steward

Whenever you gain life, you may pay {W}. If you do, put a +1/+1 counter on target creature.

Honor Troll

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

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

Light of Promise

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

Engulfing Slagwurm

Whenever Engulfing Slagwurm blocks or becomes blocked by a creature, destroy that creature. You gain life equal to that creature's toughness.

Gideon Jura

+2: During target opponent's next turn, creatures that player controls attack Gideon Jura if able.
−2: Destroy target tapped creature.
0: Until end of turn, Gideon Jura becomes a 6/6 Human Soldier creature that's still a planeswalker. Prevent all damage that would be dealt to him this turn.

Botanical Plaza

Botanical Plaza enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}, {T}, Sacrifice Botanical Plaza: Draw a card.

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 Conclave Mentor dies, you gain life equal to its power.

Reverse Damage

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.

Bottle Golems

Trample
When Bottle Golems dies, you gain life equal to its power.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Attune with Aether

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You get {E}{E} (two energy counters).

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.

Field-Tested Frying Pan

When Field-Tested Frying Pan enters, create a Food token, then create a 1/1 white Halfling creature token and attach Field-Tested Frying Pan to it.
Equipped creature has "Whenever you gain life, this creature gets +X/+X until end of turn, where X is the amount of life you gained."
Equip {2}

Etched Cornfield

Etched Cornfield enters tapped unless a player has 13 or less life.
{T}: Add {G} or {W}.

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.

Cradle of Vitality

Whenever you gain life, you may pay {1}{W}. If you do, put a +1/+1 counter on target creature for each 1 life you gained.

Archon of Redemption

Flying
Whenever Archon of Redemption or another creature you control with flying enters, you may gain life equal to that creature's power.

Sifter Wurm

Trample
When Sifter Wurm enters, scry 3, then reveal the top card of your library. You gain life equal to that card's mana value.

Graypelt Refuge

Graypelt Refuge enters tapped.
When Graypelt Refuge enters, you gain 1 life.
{T}: Add {G} or {W}.

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.

Lifeblood Hydra

Trample
Lifeblood Hydra enters with X +1/+1 counters on it.
When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

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.

Divine Offering

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

Heron of Hope

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

Flourishing Hunter

When Flourishing Hunter enters, you gain life equal to the greatest toughness among other creatures you control.

Cultivate

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.

Exotic Orchard

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

Bubbling Cauldron

{1}, {T}, Sacrifice a creature: You gain 4 life.
{1}, {T}, Sacrifice a creature named Festering Newt: Each opponent loses 4 life. You gain life equal to the life lost this way.

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.

Creosote Heath

Creosote Heath enters tapped.
When Creosote Heath enters, it deals 1 damage to target opponent.
{T}: Add {G} or {W}.

Bighorner Rancher

Vigilance
{T}: Add an amount of {G} equal to the greatest power among creatures you control.
Sacrifice Bighorner Rancher: You gain life equal to the greatest toughness among other creatures you control.

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.