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.

Staff of the Death Magus

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

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

Crypt Ghast

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.)
Whenever you tap a Swamp for mana, add an additional {B}.

Disciple of Bolas

When this creature enters, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Defile

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

Ophiomancer

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Pact Weapon

As long as this Equipment is attached to a creature, you don't lose the game for having 0 or less life.
Whenever equipped creature attacks, draw a card and reveal it. The creature gets +X/+X until end of turn and you lose X life, where X is that card's mana value.
Equip—Discard a card.

Mindwrack Harpy

Flying
At the beginning of combat on your turn, each player mills three cards.

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.)

Ayara, First of Locthwain

Whenever Ayara 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.

Prism Ring

As this artifact enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Radiant Fountain

When this land enters, you gain 2 life.
{T}: Add {C}.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Consuming Vapors

Target player sacrifices a creature of their choice. You gain life equal to that creature's toughness.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Witch of the Moors

Deathtouch
At the beginning of your end step, if you gained life this turn, each opponent sacrifices a creature of their choice and you return up to one target creature card from your graveyard to your hand.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Dread Summons

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token. (To mill a card, a player puts the top card of their library into their graveyard.)

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Swamp

Gix's Command

Choose two —
• Put two +1/+1 counters on up to one creature. It gains lifelink until end of turn.
• Destroy each creature with power 2 or less.
• Return up to two creature cards from your graveyard to your hand.
• Each opponent sacrifices a creature with the greatest power among creatures they control.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Pristine Talisman

Pontiff of Blight

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.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Veinwitch Coven

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

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

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.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

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.

Arcane Signet

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

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Night's Whisper

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.

Return to Action

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Lorcan, Warlock Collector

Flying
Whenever a creature card is put into an opponent's graveyard from anywhere, you may pay life equal to its mana value. If you do, put it onto the battlefield under your control. It's a Warlock in addition to its other types.
If a Warlock you control would die, exile it instead.

Cosmos Elixir

At the beginning of your end step, draw a card if your life total is greater than your starting life total. Otherwise, you gain 2 life.

Reckoner's Bargain

As an additional cost to cast this spell, sacrifice an artifact or creature.
You gain life equal to the sacrificed permanent's mana value. Draw two cards.

Gray Merchant of Asphodel

When this creature 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.)

Innocent Blood

Each player sacrifices a creature of their choice.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle this artifact and your graveyard into their owner's library.

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Consuming Corruption

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

Exsanguinate

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

Hero's Downfall

Sanguine Bond

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

Go for the Throat

Sheoldred, the Apocalypse

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

Demon's Disciple

When this creature enters, each player sacrifices a creature or planeswalker of their choice.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Bloodghast

This creature can't block.
This creature has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return this card from your graveyard to the battlefield.

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.

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice this artifact: Draw a card.

Consuming Sepulcher

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Tithing Blade

When this artifact enters, each opponent sacrifices a creature of their choice.
Craft with creature {4}{B} ({4}{B}, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tithing Blade // Consuming Sepulcher

Blood Artist

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

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: This artifact deals 50 damage to any target.

Sheoldred's Edict

Choose one —
• Each opponent sacrifices a nontoken creature of their choice.
• Each opponent sacrifices a creature token of their choice.
• Each opponent sacrifices a planeswalker of their choice.

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.

Village Rites

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

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.

Sol Ring

Icon of Ancestry

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik.

Zulaport Cutthroat

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

Disciple of Griselbrand

{1}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Profane Memento

Whenever a creature card is put into an opponent's graveyard from anywhere, you gain 1 life.

Font of Agonies

Whenever you pay life, put that many blood counters on this enchantment.
{1}{B}, Remove four blood counters from this enchantment: Destroy target creature.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

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.

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Liliana, Dreadhorde General

Whenever a creature you control dies, draw a card.
+1: Create a 2/2 black Zombie creature token.
−4: Each player sacrifices two creatures of their choice.
−9: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Feed the Swarm

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

Jet Medallion

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

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.

Chain Devil

Animate Chains — When this creature enters, each player sacrifices a nontoken creature of their choice.