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.)

Demonic Tutor

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

Prism Ring

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

Helm of Awakening

Rain of Filth

Until end of turn, lands you control gain "Sacrifice this land: Add {B}."

Sanguine Bond

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

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

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.

Blood Pet

Swamp

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Grim Tutor

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

Dance of the Dead

Enchant creature card in a graveyard
When Dance of the 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 Dance of the Dead." Put enchanted creature card onto the battlefield tapped under your control and attach Dance of the Dead to it. When Dance of the Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets +1/+1 and doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {1}{B}. If the player does, untap that creature.

Ancient Tomb

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

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.

Imp's Mischief

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

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.

Unstoppable Slasher

Deathtouch
Whenever Unstoppable Slasher deals combat damage to a player, they lose half their life, rounded up.
When Unstoppable Slasher dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Blood Celebrant

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

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Balthor the Defiled

Minion creatures get +1/+1.
{B}{B}{B}, Exile Balthor the Defiled: Each player returns all black and all red creature cards from their graveyard to the battlefield.

Deadly Rollick

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

Culling the Weak

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

Exquisite Blood

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

Necromancy

You may cast Necromancy as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
When Necromancy enters, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

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.

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

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.

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.

Imperial Seal

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

Beseech the Mirror

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Search your library for a card, exile it face down, then shuffle. If this spell was bargained, you may cast the exiled card without paying its mana cost if that spell's mana value is 4 or less. Put the exiled card into your hand if it wasn't cast this way.

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

Bubbling Muck

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

Dark Ritual

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.

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

Darkness

Prevent all combat damage that would be dealt this turn.

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.)

Cabal Coffers

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

Reliquary Tower

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

Phyrexian Tower

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

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

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.)

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice Crystal Vein: Add {C}{C}.

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.

Reanimate

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

The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Entomb

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

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.)

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Victim of Night

Destroy target non-Vampire, non-Werewolf, non-Zombie creature.

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Dimir House Guard

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Sacrifice a creature: Regenerate Dimir House Guard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Mastermind's Acquisition

Choose one —
• Search your library for a card, put it into your hand, then shuffle.
• Put a card you own from outside the game into your hand.

Asmodeus the Archfiend

Binding Contract — If you would draw a card, exile the top card of your library face down instead.
{B}{B}{B}: Draw seven cards.
{B}: Return all cards exiled with Asmodeus the Archfiend to their owner's hand and you lose that much life.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Cabal Ritual

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

Skirge Familiar

Sol Ring

Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

Sign in Blood

Target player draws two cards and loses 2 life.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Diabolic Tutor

Fleshwrither

Transfigure {1}{B}{B} ({1}{B}{B}, Sacrifice this creature: Search your library for a creature card with the same mana value as this creature, put that card onto the battlefield, then shuffle. Transfigure only as a sorcery.)

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Vampiric Tutor

Urborg, Tomb of Yawgmoth

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

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Lightning Greaves

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

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Cabal Stronghold

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

Bloodthirsty Conqueror

Flying, deathtouch
Whenever an opponent loses life, you gain that much life. (Damage causes loss of life.)

Sheoldred, the Apocalypse

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