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.)

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.

Defiant Bloodlord

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

Dark Ritual

Death's Duet

Return two target creature cards from your graveyard to your hand.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

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.

Swamp

Ambition's Cost

You draw three cards and you lose 3 life.

Daggerdrome Imp

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

Jet Medallion

Black spells you cast cost {1} less to cast.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

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.

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.

Preacher of the Schism

Deathtouch
Whenever Preacher of the Schism attacks the player with the most life or tied for most life, create a 1/1 white Vampire creature token with lifelink.
Whenever Preacher of the Schism attacks while you have the most life or are tied for most life, you draw a card and you lose 1 life.

Sol Ring

Knight of Dusk's Shadow

Menace (This creature can't be blocked except by two or more creatures.)
Your opponents can't gain life.
{1}{B}: Knight of Dusk's Shadow gets +1/+1 until end of turn.

Ancient Craving

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Spellbook

Crushing Disappointment

Each player loses 2 life. You draw two cards.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

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.

Exsanguinate

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

Sower of Discord

Flying
As Sower of Discord enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Stronghold Discipline

Each player loses 1 life for each creature they control.

Vampire Nighthawk

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Reliquary Tower

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Blood Pact

Target player draws two cards and loses 2 life.

Erebos, God of the Dead

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Your opponents can't gain life.
{1}{B}, Pay 2 life: Draw a card.

Demon's Due

Scry 2, then draw two cards. You lose 2 life.

Arcane Signet

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

Polluted Bonds

Whenever a land an opponent controls enters, that player loses 2 life and you gain 2 life.

Necrologia

Cast this spell only during your end step.
As an additional cost to cast this spell, pay X life.
Draw X cards.

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Commander's Sphere

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

Suffer the Past

Exile X target cards from target player's graveyard. For each card exiled this way, that player loses 1 life and you gain 1 life.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Taborax, Hope's Demise

Flying
Taborax, Hope's Demise 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.

Bloodbond Vampire

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

Exquisite Blood

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

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Sanguine Bond

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

Doom Blade

Tribute to Hunger

Target opponent sacrifices a creature. You gain life equal to that creature's toughness.

Strands of Night

{B}{B}, Pay 2 life, Sacrifice a Swamp: Return target creature card from your graveyard to the battlefield.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

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.

Staff of the Death Magus

Whenever you cast a black spell or a Swamp you control enters, you gain 1 life.

Bloodthirsty Aerialist

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

Blood Tithe

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

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Child of Night

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Defiler of Flesh

Menace
As an additional cost to cast black permanent spells, you may pay 2 life. Those spells cost {B} less to cast if you paid life this way. This effect reduces only the amount of black mana you pay.
Whenever you cast a black permanent spell, target creature you control gets +1/+1 and gains menace until end of turn.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Marauding Blight-Priest

Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)