Murderous Betrayal

{B}{B}, Pay half your life, rounded up: Destroy target nonblack creature. It can't be regenerated.

Marshland Bloodcaster

Flying
{1}{B}, {T}: Rather than pay the mana cost of the next spell you cast this turn, you may pay life equal to that spell's mana value.

Foul Imp

Flying
When Foul Imp enters, you lose 2 life.

Necrogen Scudder

Flying
When Necrogen Scudder enters, you lose 3 life.

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Succumb to Temptation

Soul Channeling

Enchant creature
Pay 2 life: Regenerate enchanted creature.

Necrologia

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

Divining Witch

{1}{B}, {T}, Discard a card: 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.

Hand of Vecna

At the beginning of combat on your turn, equipped creature or a creature you control named Vecna gets +X/+X until end of turn, where X is the number of cards in your hand.
Equip—Pay 1 life for each card in your hand.
Equip {2}

Kuro, Pitlord

At the beginning of your upkeep, sacrifice Kuro, Pitlord unless you pay {B}{B}{B}{B}.
Pay 1 life: Target creature gets -1/-1 until end of turn.

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

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.

Blood Celebrant

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

Greed

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Gallowbraid

Trample
Cumulative upkeep—Pay 1 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Blood Divination

As an additional cost to cast this spell, sacrifice a creature.
Draw three cards.

Ancient Craving

You draw three cards and 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.)

Swamp

Sisay's Ring

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Live Fast

You draw two cards, lose 2 life, and get {E}{E} (two energy counters).

Minion of the Wastes

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

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Priest of the Blood Rite

When Priest of the Blood Rite enters, create a 5/5 black Demon creature token with flying.
At the beginning of your upkeep, you lose 2 life.

Phyrexian Lens

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

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Book of Rass

Tavern Swindler

{T}, Pay 3 life: Flip a coin. If you win the flip, you gain 6 life.

Painful Lesson

Target player draws two cards and loses 2 life.

Numai Outcast

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)
{B}, Pay 5 life: Regenerate Numai Outcast.

Bog Witch

Audacious Thief

Whenever Audacious Thief attacks, you draw a card and you lose 1 life.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Unspeakable Symbol

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

Dungeon Map

{T}: Add {C}.
{3}, {T}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Sinister Concoction

{B}, Pay 1 life, Mill a card, Discard a card, Sacrifice Sinister Concoction: Destroy target creature.

Carrion Howler

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

Village Rites

Wall of Blood

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

Carnophage

At the beginning of your upkeep, tap Carnophage unless you pay 1 life.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Dark Ritual

Standing Stones

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

Leveler

When Leveler enters, exile all cards from your library.

Bane Alley Blackguard

Funeral Rites

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

Slaughter Pact

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

Grimclaw Bats

Flying
{B}, Pay 1 life: Grimclaw Bats gets +1/+1 until end of turn.

Vesper Ghoul

Phyrexian Rager

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

Souldrinker

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

Lurking Evil

Pay half your life, rounded up: Lurking Evil becomes a 4/4 Phyrexian Horror creature with flying.

Commander's Sphere

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

Midnight Reaper

Whenever a nontoken creature you control dies, Midnight Reaper deals 1 damage to you and you draw a card.

Sign in Blood

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Baleful Force

At the beginning of each upkeep, you draw a card and you lose 1 life.

Strands of Night

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