Urza's Incubator

As Urza's Incubator enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Arcane Signet

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

Curse of the Restless Dead

Enchant player
Whenever a land enchanted player controls enters, you create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

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.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

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}.

No Mercy

Whenever a creature deals damage to you, destroy it.

Magus of the Coffers

{2}, {T}: Add {B} for each Swamp you control.

Grave Titan

Deathtouch
Whenever Grave Titan enters or attacks, create two 2/2 black Zombie creature tokens.

Tendrils of Agony

Target player loses 2 life and you gain 2 life.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Sol Ring

Cunning Rhetoric

Whenever an opponent attacks you and/or one or more planeswalkers you control, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

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, Son of Yawgmoth.

Grim Tutor

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

Nirkana Revenant

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

Swamp

Thopter Squadron

Flying
Thopter Squadron enters with three +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Thopter Squadron: Create a 1/1 colorless Thopter artifact creature token with flying. Activate only as a sorcery.
{1}, Sacrifice another Thopter: Put a +1/+1 counter on Thopter Squadron. Activate only as a sorcery.

Thought Vessel

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

Imp's Mischief

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

Diregraf Colossus

Diregraf Colossus enters with a +1/+1 counter on it for each Zombie card in your graveyard.
Whenever you cast a Zombie spell, create a tapped 2/2 black Zombie creature token.

Calculating Lich

Menace
Whenever a creature attacks one of your opponents, that player loses 1 life.

Damnation

Destroy all creatures. They can't be regenerated.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Black Market

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

Cabal Paladin

Whenever you cast a historic spell, Cabal Paladin deals 2 damage to each opponent. (Artifacts, legendaries, and Sagas are historic.)

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Toxic Deluge

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

Cabal Coffers

Endrek Sahr, Master Breeder

Whenever you cast a creature spell, create X 1/1 black Thrull creature tokens, where X is that spell's mana value.
When you control seven or more Thrulls, sacrifice Endrek Sahr, Master Breeder.

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.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Liliana Vess

+1: Target player discards a card.
−2: Search your library for a card, then shuffle and put that card on top.
−8: Put all creature cards from all graveyards onto the battlefield under your control.

Marchesa's Decree

When Marchesa's Decree enters, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Koskun Falls

At the beginning of your upkeep, sacrifice Koskun Falls unless you tap an untapped creature you control.
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Aetherflux Reservoir

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

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."

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Undead Warchief

Zombie spells you cast cost {1} less to cast.
Zombie creatures you control get +2/+1.

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Blood Reckoning

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

Exsanguinate

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Jet Medallion

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

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.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Basalt Monolith

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.

Sadistic Glee

Enchant creature
Whenever a creature dies, put a +1/+1 counter on enchanted creature.

Demonic Tutor

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

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Yuan-Ti Fang-Blade

Deathtouch
Whenever Yuan-Ti Fang-Blade deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Ashnod's Altar

Mortuary

Whenever a creature is put into your graveyard from the battlefield, put that card on top of your library.

Acererak the Archlich

When Acererak the Archlich enters, if you haven't completed Tomb of Annihilation, return Acererak the Archlich to its owner's hand and venture into the dungeon.
Whenever Acererak the Archlich attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature of their choice.

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.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Urborg, Tomb of Yawgmoth

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

Baleful Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Enchanted creature gets +1/+1 and has deathtouch.

Feed the Swarm

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

Crawlspace

No more than two creatures can attack you each combat.

Pitiless Plunderer

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

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.)

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Blood Pet

Liliana of the Dark Realms

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
−3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
−6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"