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.

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Vesuva

You may have Vesuva enter tapped as a copy of any land on the battlefield.

Twilight Prophet

Flying
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, if you have the city's blessing, reveal the top card of your library and put it into your hand. Each opponent loses X life and you gain X life, where X is that card's mana value.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Accursed Marauder

When Accursed Marauder enters, each player sacrifices a nontoken creature of their choice.

Plaguecrafter

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

Entomb

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

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, the Grim 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.)

Zulaport Cutthroat

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

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Mindslicer

When Mindslicer dies, each player discards their hand.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

Fellwar Stone

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

Arcane Signet

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

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

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.

Crypt of Agadeem

Crypt of Agadeem enters tapped.
{T}: Add {B}.
{2}, {T}: Add {B} for each black creature card in your graveyard.

High Market

{T}: Add {C}.
{T}, Sacrifice a creature: You gain 1 life.

Culling the Weak

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

Gravecrawler

Gravecrawler can't block.
You may cast Gravecrawler from your graveyard as long as you control a Zombie.

Temporal Extortion

When you cast this spell, any player may pay half their life, rounded up. If a player does, counter Temporal Extortion.
Take an extra turn after this one.

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.

Ashiok, Wicked Manipulator

If you would pay life while your library has at least that many cards in it, exile that many cards from the top of your library instead.
+1: Look at the top two cards of your library. Exile one of them and put the other into your hand.
−2: Create two 1/1 black Nightmare creature tokens with "At the beginning of combat on your turn, if a card was put into exile this turn, put a +1/+1 counter on this creature."
−7: Target player exiles the top X cards of their library, where X is the total mana value of cards you own in exile.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

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}.

Imp's Mischief

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

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

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 artifact: Add one mana of any color.")

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Thought Vessel

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

Deadly Rollick

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

Dark Ritual

Sheoldred, the Apocalypse

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

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature of their choice.

Chainer, Dementia Master

All Nightmares get +1/+1.
{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.
When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Exsanguinate

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

Defile

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

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.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Reanimate

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

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Reassembling Skeleton

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

Deserted Temple

{T}: Add {C}.
{1}, {T}: Untap target land.

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Demonic Tutor

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

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature of their choice.

Feed the Swarm

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

Tainted Strike

Target creature gets +1/+0 and gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

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.

Cabal Coffers

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

Urborg, Tomb of Yawgmoth

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

Bog Witch

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Damnation

Destroy all creatures. They can't be regenerated.

Liliana, Defiant Necromancer

+2: Each player discards a card.
−X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.
−8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Liliana, Heretical Healer

Lifelink
Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

Liliana, Heretical Healer // Liliana, Defiant Necromancer

Altar of Dementia

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

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Charcoal Diamond

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

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.)

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.)

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Sol Ring

Snow-Covered Swamp

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Disciple of Bolas

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

Jet Medallion

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

Cryptbreaker

{1}{B}, {T}, Discard a card: Create a 2/2 black Zombie creature token.
Tap three untapped Zombies you control: You draw a card and you lose 1 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.)

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Ashnod's Altar

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Demonic Counsel

Search your library for a Demon card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for any card, put it into your hand, then shuffle.

Sidisi, Undead Vizier

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When Sidisi, Undead Vizier exploits a creature, you may search your library for a card, put it into your hand, then shuffle.

Reliquary Tower

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Vile Entomber

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, search your library for a card, put that card into your graveyard, then shuffle.