Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Plague of Vermin

Starting with you, each player may pay any amount of life. Repeat this process until no one pays life. Each player creates a 1/1 black Rat creature token for each 1 life they paid this way.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Souldrinker

Pay 3 life: Put a +1/+1 counter on Souldrinker.

Demon's Due

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

Tarnished Citadel

{T}: Add {C}.
{T}: Add one mana of any color. Tarnished Citadel deals 3 damage to you.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Shadowcloak Vampire

Pay 2 life: Shadowcloak Vampire gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)

Selenia, Dark Angel

Flying
Pay 2 life: Return Selenia, Dark Angel to its owner's hand.

Arcane Signet

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

Vault of Champions

Vault of Champions enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Intervention Pact

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.
At the beginning of your next upkeep, pay {1}{W}{W}. If you don't, you lose the game.

Infernal Grasp

Destroy target creature. You lose 2 life.

Reign of Terror

Destroy all green creatures or all white creatures. They can't be regenerated. You lose 2 life for each creature that died this way.

Swamp

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Tainted Field

{T}: Add {C}.
{T}: Add {W} or {B}. Activate only if you control a Swamp.

Shattered Sanctum

Shattered Sanctum enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Raving Oni-Slave

When Raving Oni-Slave enters or leaves the battlefield, you lose 3 life if you don't control a Demon.

Ethereal Champion

Pay 1 life: Prevent the next 1 damage that would be dealt to Ethereal Champion this turn.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Soul Channeling

Enchant creature
Pay 2 life: Regenerate enchanted creature.

Phyrexian Rager

When Phyrexian Rager enters the battlefield, you draw a card and you lose 1 life.

Skeletal Scrying

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and you lose X life.

Ambition's Cost

You draw three cards and you lose 3 life.

Vizkopa Confessor

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.)
When Vizkopa Confessor enters the battlefield, pay any amount of life. Target opponent reveals that many cards from their hand. You choose one of them and exile it.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Grand Coliseum

Grand Coliseum enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Grand Coliseum deals 1 damage to you.

Serum Powder

{T}: Add {C}.
Any time you could mulligan and Serum Powder is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Eye of Vecna

When Eye of Vecna enters the battlefield, you draw a card and you lose 2 life.
At the beginning of your upkeep, you may pay {2}. If you do, you draw a card and you lose 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.

Tomb of Urami

{T}: Add {B}. Tomb of Urami deals 1 damage to you if you don't control an Ogre.
{2}{B}{B}, {T}, Sacrifice all lands you control: Create Urami, a legendary 5/5 black Demon Spirit creature token with flying.

Tethered Skirge

Flying
Whenever Tethered Skirge becomes the target of a spell or ability, you lose 1 life.

Phyrexian Processor

As Phyrexian Processor enters the battlefield, pay any amount of life.
{4}, {T}: Create an X/X black Phyrexian Minion creature token, where X is the life paid as Phyrexian Processor entered the battlefield.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Shattered Crypt

Return X target creature cards from your graveyard to your hand. You lose X life.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Salt Flats

Salt Flats enters the battlefield tapped.
{T}: Add {C}.
{T}: Add {W} or {B}. Salt Flats deals 1 damage to you.

Plains

Fathom Fleet Boarder

When Fathom Fleet Boarder enters the battlefield, you lose 2 life unless you control another Pirate.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Foul Imp

Flying
When Foul Imp enters the battlefield, you lose 2 life.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Ancient Craving

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Carrion Howler

Pay 1 life: Carrion Howler gets +2/-1 until end of turn.

Cabal Pit

{T}: Add {B}. Cabal Pit deals 1 damage to you.
Threshold — {B}, {T}, Sacrifice Cabal Pit: Target creature gets -2/-2 until end of turn. Activate only if seven or more cards are in your graveyard.

Fetid Heath

{T}: Add {C}.
{W/B}, {T}: Add {W}{W}, {W}{B}, or {B}{B}.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Glorifier of Dusk

Pay 2 life: Glorifier of Dusk gains flying until end of turn.
Pay 2 life: Glorifier of Dusk gains vigilance until end of turn.

Crovax, Ascendant Hero

Other white creatures get +1/+1.
Nonwhite creatures get -1/-1.
Pay 2 life: Return Crovax, Ascendant Hero to its owner's hand.

Adanto Vanguard

As long as Adanto Vanguard is attacking, it gets +2/+0.
Pay 4 life: Adanto Vanguard gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Sorrow's Path

{T}: Choose two target blocking creatures an opponent controls. If each of those creatures could block all creatures that the other is blocking, remove both of them from combat. Each one then blocks all creatures the other was blocking.
Whenever Sorrow's Path becomes tapped, it deals 2 damage to you and each creature you control.

Dark Ritual

Necrogen Scudder

Flying
When Necrogen Scudder enters the battlefield, you lose 3 life.

Martyrs' Tomb

Pay 2 life: Prevent the next 1 damage that would be dealt to target creature this turn.

Toxic Abomination

When Toxic Abomination enters the battlefield, you lose 2 life.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Blood Price

Look at the top four cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order. You lose 2 life.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Minion of the Wastes

Trample
As Minion of the Wastes enters the battlefield, pay any amount of life.
Minion of the Wastes's power and toughness are each equal to the life paid as it entered the battlefield.

Reckless Spite

Destroy two target nonblack creatures. You lose 5 life.

Ulcerate

Target creature gets -3/-3 until end of turn. You lose 3 life.

Serpent Warrior

When Serpent Warrior enters the battlefield, you lose 3 life.

Ebon Drake

Flying
Whenever a player casts a spell, you lose 1 life.

Boon of Erebos

Target creature gets +2/+0 until end of turn. Regenerate it. You lose 2 life.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Demonic Consultation

Choose a card name. Exile the top six cards of your library, then reveal cards from the top of your library until you reveal a card with the chosen name. Put that card into your hand and exile all other cards revealed this way.

Deepwood Ghoul

Arco-Flagellant

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters the battlefield, create that many tokens that are copies of it.)
Arco-Flagellant can't block.
Endurant — Pay 3 life: Arco-Flagellant gains indestructible until end of turn.

Silent Clearing

{T}, Pay 1 life: Add {W} or {B}.
{1}, {T}, Sacrifice Silent Clearing: Draw a card.

Transcendence

You don't lose the game for having 0 or less life.
When you have 20 or more life, you lose the game.
Whenever you lose life, you gain 2 life for each 1 life you lost. (Damage dealt to you causes you to lose life.)

Mischievous Poltergeist

Flying
Pay 1 life: Regenerate Mischievous Poltergeist.

Read the Bones

Bitter Revelation

Look at the top four cards of your library. Put two of them into your hand and the rest into your graveyard. You lose 2 life.

Orzhov Signet

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Spoils of the Vault

Choose a card name. Reveal cards from the top of your library until you reveal a card with that name, then put that card into your hand. Exile all other cards revealed this way, and you lose 1 life for each of the exiled cards.