Theater of Horrors

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with this enchantment.
{3}{R}: This enchantment deals 1 damage to target opponent or planeswalker.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Pain Distributor

Menace
Whenever a player casts their first spell each turn, they create a Treasure token.
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, this creature deals 1 damage to that player.

Mind Stone

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

Lethal Exploit

Target creature gets -2/-2 until end of turn. It gets an additional -1/-1 until end of turn for each modified creature you controlled as you cast this spell. (Equipment, Auras you control, and counters are modifications.)

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Nazgûl

Deathtouch
When this creature enters, the Ring tempts you.
Whenever the Ring tempts you, put a +1/+1 counter on each Wraith you control.
A deck can have up to nine cards named Nazgûl.

Archpriest of Shadows

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Deathtouch
Whenever this creature deals combat damage to a player or battle, return target creature card from your graveyard to the battlefield.

Skyclave Shadowcat

{1}{B}, Sacrifice another creature: Put a +1/+1 counter on this creature.
Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

Life of the Party

First strike, trample, haste
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of creatures you control.
When this creature enters, if it's not a token, each opponent creates a token that's a copy of it. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

Grim Hireling

Whenever one or more creatures you control deal combat damage to a player, create two Treasure tokens.
{B}, Sacrifice X Treasures: Target creature gets -X/-X until end of turn. Activate only as a sorcery.

Nikara, Lair Scavenger

Partner with Yannik, Scavenging Sentinel (When this creature enters, target player may put Yannik into their hand from their library, then shuffle.)
Menace
Whenever another creature you control leaves the battlefield, if it had one or more counters on it, you draw a card and you lose 1 life.

Pirate's Pillage

Prosper, Tome-Bound

Deathtouch
Mystic Arcanum — At the beginning of your end step, exile the top card of your library. Until the end of your next turn, you may play that card.
Pact Boon — Whenever you play a card from exile, create a Treasure token.

Sauron, the Necromancer

Menace
Whenever Sauron attacks, exile target creature card from your graveyard. Create a tapped and attacking token that's a copy of that card, except it's a 3/3 black Wraith with menace. At the beginning of the next end step, exile that token unless Sauron is your Ring-bearer.

Mirror-Style Master

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature attacks, for each attacking modified creature you control, create a tapped and attacking token that's a copy of that creature. Exile those tokens at end of combat. (Equipment, Auras you control, and counters are modifications.)

Rakdos, Lord of Riots

You can't cast Rakdos unless an opponent lost life this turn.
Flying, trample
Creature spells you cast cost {1} less to cast for each 1 life your opponents have lost this turn.

Immersturm Predator

Flying
Whenever this creature becomes tapped, exile up to one target card from a graveyard and put a +1/+1 counter on this creature.
Sacrifice another creature: This creature gains indestructible until end of turn. Tap it.

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Thundering Raiju

Haste
Whenever this creature attacks, put a +1/+1 counter on target creature you control. Then this creature deals X damage to each opponent, where X is the number of modified creatures you control other than this creature. (Equipment, Auras you control, and counters are modifications.)

Necropolis Regent

Flying
Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Swamp

Exava, Rakdos Blood Witch

First strike, haste
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Each other creature you control with a +1/+1 counter on it has haste.

Bedazzle

Destroy target nonbasic land. Bedazzle deals 2 damage to target opponent or planeswalker.

Bedeck

Target creature gets +3/-3 until end of turn.

Bedeck // Bedazzle

Rakdos Cackler

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Dockside Extortionist

When this creature enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Carnival Hellsteed

First strike, haste
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Uncivil Unrest

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)
If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Wheel of Misfortune

Each player secretly chooses a number 0 or greater, then all players reveal those numbers simultaneously and determine the highest and lowest numbers revealed this way. Wheel of Misfortune deals damage equal to the highest number to each player who chose that number. Each player who didn't choose the lowest number discards their hand, then draws seven cards.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Cinderbones

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{1}{B}: Regenerate this creature.

Master of Cruelties

First strike, deathtouch
This creature can only attack alone.
Whenever this creature attacks a player and isn't blocked, that player's life total becomes 1. This creature assigns no combat damage this combat.

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Bloodfray Giant

Trample
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Bedevil

Destroy target artifact, creature, or planeswalker.

Rakdos Signet

Fists of the Demigod

Enchant creature
As long as enchanted creature is black, it gets +1/+1 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
As long as enchanted creature is red, it gets +1/+1 and has first strike.

Cryptborn Horror

Trample
This creature enters with X +1/+1 counters on it, where X is the total life lost by your opponents this turn.

Command Tower

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

Splatter Thug

First strike
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Arcane Signet

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Mountain

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Kulrath Knight

Flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Creatures your opponents control with counters on them can't attack or block.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Kalain, Reclusive Painter

When Kalain enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Other creatures you control enter with an additional +1/+1 counter on them for each mana from a Treasure spent to cast them.

Humble Defector

{T}: Draw two cards. Target opponent gains control of this creature. Activate only during your turn.

Kami of Celebration

Whenever a modified creature you control attacks, exile the top card of your library. You may play that card this turn. (Equipment, Auras you control, and counters are modifications.)
Whenever you cast a spell from exile, put a +1/+1 counter on target creature you control.

Hellhole Flailer

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
{2}{B}{R}, Sacrifice this creature: It deals damage equal to its power to target player or planeswalker.

Contagion Clasp

When this artifact enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sign in Blood

Target player draws two cards and loses 2 life.

Auger Spree

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

Call of the Ring

At the beginning of your upkeep, the Ring tempts you.
Whenever you choose a creature as your Ring-bearer, you may pay 2 life. If you do, draw a card.

Witch-king of Angmar

Flying
Whenever one or more creatures deal combat damage to you, each opponent sacrifices a creature of their choice that dealt combat damage to you this turn. The Ring tempts you.
Discard a card: Witch-king of Angmar gains indestructible until end of turn. Tap it.

Carnage

Carnage deals 3 damage to target opponent. That player discards two cards.

Carnival

Carnival deals 1 damage to target creature or planeswalker and 1 damage to that permanent's controller.

Carnival // Carnage

Hagra Constrictor

This creature enters with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has menace. (A creature with menace can't be blocked except by two or more creatures.)

Flayer of the Hatebound

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)
Whenever this creature or another creature enters from your graveyard, that creature deals damage equal to its power to any target.

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.