Culling the Weak

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

Megrim

Whenever an opponent discards a card, this enchantment deals 2 damage to that player.

No Mercy

Whenever a creature deals damage to you, destroy it.

Jet Medallion

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

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

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.

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.

Mindslicer

When this creature dies, each player discards their hand.

Iron Maiden

At the beginning of each opponent's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.

Arcane Signet

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

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Bubbling Muck

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

Swamp

Cabal Coffers

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

Thought Vessel

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

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, 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}.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Feed the Swarm

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

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Seizan, Perverter of Truth

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Gixian Puppeteer

Whenever you draw your second card each turn, each opponent loses 2 life and you gain 2 life.
When this creature dies, return another target creature card with mana value 3 or less from your graveyard to the battlefield.

Sheoldred, the Apocalypse

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

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature 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.

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.

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.)

Vampiric Tutor

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

Phyrexian Arena

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

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Caged Sun

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Exquisite Blood

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

Imp's Mischief

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

Sol Ring

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Greed

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.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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.)

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.

Reliquary Tower

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Ivory Tower

At the beginning of your upkeep, you gain X life, where X is the number of cards in your hand minus 4.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Demonic Tutor

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

Magus of the Coffers

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control of their choice. Round up each time.

Underworld Dreams

Whenever an opponent draws a card, this enchantment deals 1 damage to that player.

Rain of Filth

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

Fellwar Stone

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

Temple Bell

Dark Ritual

Toxic Deluge

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

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Scrawling Crawler

At the beginning of your upkeep, each player draws a card.
Whenever an opponent draws a card, that player loses 1 life.

Oppression

Whenever a player casts a spell, that player discards a card.

Darkness

Prevent all combat damage that would be dealt this turn.

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.

Price of Knowledge

Players have no maximum hand size.
At the beginning of each opponent's upkeep, this enchantment deals damage to that player equal to the number of cards in that player's hand.

Orcish Bowmasters

Flash
When this creature enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, this creature deals 1 damage to any target. Then amass Orcs 1.

Viseling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is the number of cards in their hand minus 4.

Cabal Ritual

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

Urborg, Tomb of Yawgmoth

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

Black Vise

As this artifact enters, choose an opponent.
At the beginning of the chosen player's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.