Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

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.

Bloodthirsty Aerialist

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

Beacon of Immortality

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

Vona, Butcher of Magan

Vigilance, lifelink
{T}, Pay 7 life: Destroy target nonland permanent. Activate only during your turn.

Tower of Eons

Revenge

Double your life total. Target opponent loses half their life, rounded up.

Revival

Return target creature card with mana value 3 or less from your graveyard to the battlefield.

Revival // Revenge

Ayli, Eternal Pilgrim

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
{1}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness.
{1}{W}{B}, Sacrifice another creature: Exile target nonland permanent. Activate only if you have at least 10 life more than your starting life total.

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.

Veinwitch Coven

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

Crypt Ghast

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.)
Whenever you tap a Swamp for mana, add an additional {B}.

Ordeal of Heliod

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Heliod.
When you sacrifice Ordeal of Heliod, you gain 10 life.

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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.

Blind Obedience

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.)
Artifacts and creatures your opponents control enter tapped.

Scion of the Swarm

Flying
Whenever you gain life, put a +1/+1 counter on Scion of the Swarm.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Rest for the Weary

Target player gains 4 life.
Landfall — If you had a land enter the battlefield under your control this turn, that player gains 8 life instead.

Agent of Masks

At the beginning of your upkeep, each opponent loses 1 life. You gain life equal to the life lost this way.

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.

Defiant Bloodlord

Flying
Whenever you gain life, target opponent loses that much life.

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.

Sunspring Expedition

Landfall — Whenever a land enters under your control, you may put a quest counter on Sunspring Expedition.
Remove three quest counters from Sunspring Expedition and sacrifice it: You gain 8 life.

Angel's Mercy

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.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

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.

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.

Dogged Pursuit

At the beginning of your end step, each opponent loses 1 life and you gain 1 life.

Righteous Valkyrie

Flying
Whenever another Angel or Cleric you control enters, you gain life equal to that creature's toughness.
As long as you have at least 7 life more than your starting life total, creatures you control get +2/+2.

Meditation Puzzle

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.)
You gain 8 life.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X 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.

Grave Endeavor

Roll two d10 and choose one result. Return a creature card from your graveyard to the battlefield with a number of +1/+1 counters on it equal to that result. Then each opponent loses X life and you gain X life, where X is the other result.

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.

Curse of Fool's Wisdom

Enchant player
Whenever enchanted player draws a card, they lose 2 life and you gain 2 life.
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

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.

Sorin's Vengeance

Sorin's Vengeance deals 10 damage to target player or planeswalker and you gain 10 life.

Campaign of Vengeance

Whenever a creature you control attacks, defending player loses 1 life and you gain 1 life.

Blood Baron of Vizkopa

Lifelink, protection from white and from black
As long as you have 30 or more life and an opponent has 10 or less life, Blood Baron of Vizkopa gets +6/+6 and has flying.

Glorious Enforcer

Flying, lifelink
At the beginning of each combat, if you have more life than an opponent, Glorious Enforcer gains double strike until end of turn.

Debt to the Deathless

Each opponent loses two times X life. You gain life equal to the life lost this way.

Cliffhaven Vampire

Flying
Whenever you gain life, 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.

Light of Promise

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

Hierophant's Chalice

When Hierophant's Chalice enters, target opponent loses 1 life and you gain 1 life.
{T}: Add {C}.

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.

Test of Endurance

At the beginning of your upkeep, if you have 50 or more life, you win the game.

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.

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.

Feudkiller's Verdict

You gain 10 life. Then if you have more life than an opponent, create a 5/5 white Giant Warrior creature token.

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.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Plains

Invincible Hymn

Count the number of cards in your library. Your life total becomes that number.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Lich's Mastery

Hexproof
You can't lose the game.
Whenever you gain life, draw that many cards.
Whenever you lose life, for each 1 life you lost, exile a permanent you control or a card from your hand or graveyard.
When Lich's Mastery leaves the battlefield, you lose the game.

Font of Vigor

{2}{W}, Sacrifice Font of Vigor: You gain 7 life.

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.

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.

Alhammarret's Archive

If you would gain life, you gain twice that much life instead.
If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Boon Reflection

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

Celestial Mantle

Enchant creature
Enchanted creature gets +3/+3.
Whenever enchanted creature deals combat damage to a player, double its controller's life total.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

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.)

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.