Oloro, Ageless Ascetic

At the beginning of your upkeep, you gain 2 life.
Whenever you gain life, you may pay {1}. If you do, draw a card and each opponent loses 1 life.
At the beginning of your upkeep, if Oloro, Ageless Ascetic is in the command zone, you gain 2 life.

Infiltrator's Magemark

Enchant creature
Creatures you control that are enchanted get +1/+1 and can't be blocked except by creatures with defender.

Invisibility

Enchant creature
Enchanted creature can't be blocked except by Walls.

Sol Ring

Cloudblazer

Flying
When this creature enters, you gain 2 life and draw two cards.

Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Celestial Unicorn

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

Vampire Scrivener

Flying
Whenever you gain life during your turn, put a +1/+1 counter on Vampire Scrivener.
Whenever you lose life during your turn, put a +1/+1 counter on Vampire Scrivener.

Protective Bubble

Enchant creature
Enchanted creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)

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.

Sunbond

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

Aether Tunnel

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.

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.)

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.

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

Skyblinder Staff

Equipped creature gets +1/+0 and can't be blocked by creatures with flying.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

Nihiloor

When Nihiloor enters, for each opponent, tap up to one untapped creature you control. When you do, gain control of target creature that player controls with power less than or equal to the tapped creature's power for as long as you control Nihiloor.
Whenever you attack with a creature an opponent owns, you gain 2 life and that player loses 2 life.

Bloodbond Vampire

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

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Azorius Charm

Choose one —
• Creatures you control gain lifelink until end of turn.
• Draw a card.
• Put target attacking or blocking creature on top of its owner's library.

Enter the God-Eternals

Enter the God-Eternals deals 4 damage to target creature and you gain life equal to the damage dealt this way. Target player mills four cards. Amass Zombies 4. (Put four +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Vizkopa Guildmage

{1}{W}{B}: Target creature gains lifelink until end of turn.
{1}{W}{B}: Whenever you gain life this turn, each opponent loses that much life.

Bloodthirsty Aerialist

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

Veinwitch Coven

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

Chitinous Cloak

Equipped creature gets +2/+2 and has menace. (It can't be blocked except by two or more creatures.)
Equip {3}

Vanguard Suppressor

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Flying
Suppressing Fire — Whenever Vanguard Suppressor deals combat damage to a player, draw a card.

Plains

Ajani's Pridemate

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

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Skeleton Key

Equipped creature has skulk. (It can't be blocked by creatures with greater power.)
Whenever equipped creature deals combat damage to a player, you may draw a card. If you do, discard a card.
Equip {2}

Absorb

Defiant Bloodlord

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

Ultramarines Honour Guard

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Other creatures you control get +1/+1.

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.

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.

Swamp

Cloak of Mists

Enchant creature
Enchanted creature can't be blocked.

Augury Adept

Whenever Augury Adept deals combat damage to a player, reveal the top card of your library and put that card into your hand. You gain life equal to its mana value.

Famished Paladin

Famished Paladin doesn't untap during your untap step.
Whenever you gain life, untap Famished Paladin.

Scion of the Swarm

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

Hot Soup

Equipped creature can't be blocked.
Whenever equipped creature is dealt damage, destroy it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Sphinx of the Steel Wind

Flying, first strike, vigilance, lifelink, protection from red and from green

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Sanguine Bond

Whenever you gain life, target opponent loses that much 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.

Marauding Blight-Priest

Cloak of Invisibility

Enchant creature
Enchanted creature has phasing and can't be blocked except by Walls. (It phases in or out before its controller untaps during each of their untap steps. While it's phased out, it's treated as though it doesn't exist.)

Gutter Shortcut

Enchant creature
Enchanted creature can't be blocked as long as it's attacking alone.
If Gutter Shortcut would be put into a graveyard from anywhere, exile it instead.

Gutter Skulker

Gutter Skulker can't be blocked as long as it's attacking alone.
Disturb {3}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Gutter Skulker // Gutter Shortcut

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

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.

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.

Kalastria Nightwatch

Whenever you gain life, Kalastria Nightwatch gains flying until end of turn.

Deny the Witch

Counter target spell, activated ability, or triggered ability. Its controller loses life equal to the number of creatures you control.

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Sphinx Sovereign

Flying
At the beginning of your end step, you gain 3 life if Sphinx Sovereign is untapped. Otherwise, each opponent loses 3 life.

Drogskol Reaver

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, draw a card.

Celestine, the Living Saint

Flying, lifelink
Healing Tears — At the beginning of your end step, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.

Island

Reviving Vapors

Reveal the top three cards of your library and put one of them into your hand. You gain life equal to that card's mana value. Put all other cards revealed this way into your graveyard.

Light of Promise

Daxos of Meletis

Daxos of Meletis can't be blocked by creatures with power 3 or greater.
Whenever Daxos of Meletis deals combat damage to a player, exile the top card of that player's library. You gain life equal to that card's mana value. Until end of turn, you may cast that card and you may spend mana as though it were mana of any color to cast that spell.

Exquisite Blood

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

Magister Sphinx

Flying
When Magister Sphinx enters, target player's life total becomes 10.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

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.