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.

Dark Deal

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

Tinybones Joins Up

When Tinybones Joins Up enters, any number of target players each discard a card.
Whenever a legendary creature you control enters, any number of target players each mill a card and lose 1 life.

Sign in Blood

Target player draws two cards and loses 2 life.

Diabolic Tutor

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

Underworld Dreams

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

Demonic Tutor

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.

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.

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

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.

Sheoldred, the Apocalypse

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

Mind Sludge

Target player discards a card for each Swamp you control.

Rakshasa's Secret

Target opponent discards two cards. You mill two cards.

Distress

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Lay Bare the Heart

Target opponent reveals their hand. You choose a nonlegendary, nonland card from it. That player discards that card.

Arcane Signet

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

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.

Reanimate

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

Shrouded Lore

Target opponent chooses a card in your graveyard. You may pay {B}. If you do, repeat this process except that opponent can't choose a card already chosen for Shrouded Lore. Then put the last chosen card into your hand.

Long Goodbye

This spell can't be countered. (This includes by the ward ability.)
Destroy target creature or planeswalker with mana value 3 or less.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

Deadbridge Shaman

When this creature dies, target opponent discards a card.

Syphon Flesh

Each other player sacrifices a creature. You create a 2/2 black Zombie creature token for each creature sacrificed this way.

Barter in Blood

Each player sacrifices two creatures of their choice.

Memory Theft

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. You may put a card that has an Adventure that player owns from exile into that player's graveyard.

Gravedigger

When this creature enters, you may return target creature card from your graveyard to your hand.

Hypnotic Specter

Flying
Whenever this creature deals damage to an opponent, that player discards a card at random.

Horrifying Revelation

Target player discards a card, then mills a card.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Mind Shatter

Target player discards X cards at random.

Culling the Weak

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

Mental Agony

Target player discards two cards and loses 2 life.

Black Cat

When this creature dies, target opponent discards a card at random.

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Swamp

Tinybones, Bauble Burglar

Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it.
During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells.
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Ravenous Rats

When this creature enters, target opponent discards a card.

Mind Rot

Sanguine Bond

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

Triumph of Cruelty

At the beginning of your upkeep, target opponent discards a card if you control the creature with the greatest power or tied for the greatest power.

Ebon Stronghold

This land enters tapped.
{T}: Add {B}.
{T}, Sacrifice this land: Add {B}{B}.

Torment of Scarabs

Enchant player
At the beginning of enchanted player's upkeep, that player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.

Spellbook

Oppression

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

Chain of Smog

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

Ashnod's Altar

Piranha Marsh

This land enters tapped.
When this land enters, target player loses 1 life.
{T}: Add {B}.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Sol Ring

Dark Ritual

Final Parting

Search your library for two cards. Put one into your hand and the other into your graveyard. Then shuffle.

Blackmail

Target player reveals three cards from their hand and you choose one of them. That player discards that card.

Command Tower

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Coercion

Target opponent reveals their hand. You choose a card from it. That player discards that card.

Wrench Mind

Target player discards two cards unless they discard an artifact card.

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel deals 2 damage to them.
−1: Target player discards a card.

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.

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Drill Bit

Spectacle {B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

The Stasis Coffin

{2}, {T}, Exile The Stasis Coffin: You gain protection from everything until your next turn.

Disciple of Phenax

When this creature enters, target player reveals a number of cards from their hand equal to your devotion to black. You choose one of them. That player discards that card. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Animate Dead

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

Ordeal of Erebos

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice this Aura.
When you sacrifice this Aura, target player discards two cards.

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.)

Mire's Toll

Target player reveals a number of cards from their hand equal to the number of Swamps you control. You choose one of them. That player discards that card.

Mindstab Thrull

Whenever this creature attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Damnation

Destroy all creatures. They can't be regenerated.

Bojuka Bog

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

Temple of the False God

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

Megrim

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

Exquisite Blood

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

Haunting Hymn

Target player discards two cards. If you cast this spell during your main phase, that player discards four cards instead.