Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Scion of the Swarm

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

Taborax, Hope's Demise

Flying
Taborax has lifelink as long as it has five or more +1/+1 counters on it.
Whenever another nontoken creature you control dies, put a +1/+1 counter on Taborax. If that creature was a Cleric, you may draw a card. If you do, you lose 1 life.

Ghastly Gloomhunter

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Flying, lifelink
If this creature was kicked, it enters with two +1/+1 counters on it.

Syphon Soul

Syphon Soul deals 2 damage to each other player. You gain life equal to the damage dealt this way.

Vampire Scrivener

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

Tivash, Gloom Summoner

Lifelink
At the beginning of your end step, if you gained life this turn, you may pay X life, where X is the amount of life you gained this turn. If you do, create an X/X black Demon creature token with flying.

Agate-Blade Assassin

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

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.

Arrogant Outlaw

When this creature enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

Deep-Cavern Bat

Flying, lifelink
When this creature enters, look at target opponent's hand. You may exile a nonland card from it until this creature leaves the battlefield.

Chancellor of the Dross

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent loses 3 life, then you gain life equal to the life lost this way.
Flying, lifelink

Mask of Griselbrand

Equipped creature has flying and lifelink.
Whenever equipped creature dies, you may pay X life, where X is its power. If you do, draw X cards.
Equip {3}

Banehound

Mark of the Oni

Enchant creature
You control enchanted creature.
At the beginning of the end step, if you control no Demons, sacrifice this Aura.

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.)

Acolyte of Aclazotz

{T}, Sacrifice another creature or artifact: Each opponent loses 1 life and you gain 1 life.

Subversion

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

Nullpriest of Oblivion

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Lifelink
Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, if it was kicked, return target creature card from your graveyard to the battlefield.

Creeping Bloodsucker

At the beginning of your upkeep, this creature deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

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.

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on this creature.
{5}{B}{B}, Sacrifice this creature: Target player loses X life, where X is this creature's power.

Butcher's Cleaver

Equipped creature gets +3/+0.
As long as equipped creature is a Human, it has lifelink.
Equip {3}

Alchemist's Gift

Target creature gets +1/+1 and gains your choice of deathtouch or lifelink until end of turn. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it. Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Absorb Vis

Target player loses 4 life and you gain 4 life.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Veinwitch Coven

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

Duskfang Mentor

When this creature enters, put a lifelink counter on target non-Human creature you control.
{1}{B}, {T}: Put a +1/+1 counter on each creature you control with lifelink.

Bloodthirsty Aerialist

Bottle Golems

Trample
When this creature dies, you gain life equal to its power.

Archfiend's Vessel

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, if it entered from your graveyard or you cast it from your graveyard, exile it. If you do, create a 5/5 black Demon creature token with flying.

Bloodline Necromancer

Lifelink
When this creature enters, you may return target Vampire or Wizard creature card from your graveyard to the battlefield.

Weed Strangle

Destroy target creature. Clash with an opponent. If you win, you gain life equal to that creature's toughness. (Each clashing player reveals the top card of their library, then puts that card on their choice of the top or bottom. A player wins if their card had a greater mana value.)

Phial of Galadriel

If you would draw a card while you have no cards in hand, draw two cards instead.
If you would gain life while you have 5 or less life, you gain twice that much life instead.
{T}: Add one mana of any color.

Gifted Aetherborn

Blood Glutton

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Blessing of Belzenlok

Target creature gets +2/+1 until end of turn. If it's legendary, it also gains lifelink until end of turn.

Blood Burglar

During your turn, this creature has lifelink.(Damage dealt by this creature also causes you to gain that much life.)

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Malakir Familiar

Flying, deathtouch
Whenever you gain life, this creature gets +1/+1 until end of turn.

Noxious Gearhulk

Menace
When this creature enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Demonic Covenant

Whenever one or more Demons you control attack a player, you draw a card and lose 1 life.
At the beginning of your end step, create a 5/5 black Demon creature token with flying, then mill two cards. If two cards that share all their card types were milled this way, sacrifice this enchantment.

Archfiend of Spite

Flying
Whenever a source an opponent controls deals damage to this creature, that source's controller loses that much life unless they sacrifice that many permanents of their choice.
Madness {3}{B}{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.)

Grimdancer

This creature enters with your choice of two different counters on it from among menace, deathtouch, and lifelink.

Cutthroat Maneuver

Up to two target creatures each get +1/+1 and gain lifelink until end of turn.

Bushmeat Poacher

{1}, {T}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness. Draw a card.

Creeping Chill

Creeping Chill deals 3 damage to each opponent and you gain 3 life.
When Creeping Chill is put into your graveyard from your library, you may exile it. If you do, Creeping Chill deals 3 damage to each opponent and you gain 3 life.

Nirkana Assassin

Whenever you gain life, this creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Arcane Signet

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

Abattoir Ghoul

First strike
Whenever a creature dealt damage by this creature this turn dies, you gain life equal to that creature's toughness.

Ardyn, the Usurper

Demons you control have menace, lifelink, and haste.
Starscourge — At the beginning of combat on your turn, exile up to one target creature card from a graveyard. If you exiled a card this way, create a token that's a copy of that card, except it's a 5/5 black Demon.

Burden of Greed

Target player loses 1 life for each tapped artifact they control.

Bloodbond Vampire

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

Nighthawk Scavenger

Flying, deathtouch, lifelink
Nighthawk Scavenger's power is equal to 1 plus the number of card types among cards in your opponents' graveyards.

Venomcrawler

Lifelink
Devourer of Souls — Whenever another creature dies, put a +1/+1 counter on this creature.

Rite of Consumption

As an additional cost to cast this spell, sacrifice a creature.
Rite of Consumption deals damage equal to the sacrificed creature's power to target player or planeswalker. You gain life equal to the damage dealt this way.

Child of Night

Defiant Bloodlord

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

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Escaped Null

Lifelink
Whenever this creature blocks or becomes blocked, it gets +5/+0 until end of turn.

Blood Tribute

Kicker—Tap an untapped Vampire you control. (You may tap a Vampire you control in addition to any other costs as you cast this spell.)
Target opponent loses half their life, rounded up. If this spell was kicked, you gain life equal to the life lost this way.

Chalice of Death

Chalice of Life

{T}: You gain 1 life. Then if you have at least 10 life more than your starting life total, transform this artifact.

Chalice of Life // Chalice of Death

Blood Host

{1}{B}, Sacrifice another creature: Put a +1/+1 counter on this creature and you gain 2 life.

Blight Mound

Attacking Pests you control get +1/+0 and have menace.
Whenever a nontoken creature you control dies, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

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.

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.

Plague Drone

Flying
Rot Fly — If an opponent would gain life, that player loses that much life instead.

Al Bhed Salvagers

Whenever this creature or another creature or artifact you control dies, target opponent loses 1 life and you gain 1 life.

Echo of Dusk

Descend 4 — As long as there are four or more permanent cards in your graveyard, this creature gets +1/+1 and has lifelink.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.