Counterspell

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.)

Bojuka Bog

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

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Venomcrawler

Lifelink
Devourer of Souls — Whenever another creature dies, put a +1/+1 counter on Venomcrawler.

Molten Slagheap

{T}: Add {C}.
{1}, {T}: Put a storage counter on Molten Slagheap.
{1}, Remove X storage counters from Molten Slagheap: Add X mana in any combination of {B} and/or {R}.

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

Overseer of the Damned

Flying
When Overseer of the Damned enters, you may destroy target creature.
Whenever a nontoken creature an opponent controls dies, create a tapped 2/2 black Zombie creature token.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Arcane Signet

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

Forbid

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell.

Morbid Plunder

Return up to two target creature cards from your graveyard to your hand.

Island

Barren Moor

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

Rakdos, Lord of Riots

You can't cast Rakdos, Lord of Riots 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.

Bloodgift Demon

Flying
At the beginning of your upkeep, target player draws a card and loses 1 life.

Swamp

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.

Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Herald of Slaanesh

Locus of Slaanesh — Demon spells you cast cost {2} less to cast.
Other Demons you control have haste.

Cancel

Izzet Signet

Rakdos Signet

Reaper from the Abyss

Flying
Morbid — At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Disentomb

Return target creature card from your graveyard to your hand.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Exotic Orchard

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

Lord Xander, the Collector

When Lord Xander, the Collector enters, target opponent discards half the cards in their hand, rounded down.
Whenever Lord Xander attacks, defending player mills half their library, rounded down.
When Lord Xander dies, target opponent sacrifices half the nonland permanents they control of their choice, rounded down.

Be'lakor, the Dark Master

Flying
Prince of Chaos — When Be'lakor, the Dark Master enters, you draw X cards and you lose X life, where X is the number of Demons you control.
Lord of Torment — Whenever another Demon you control enters, it deals damage equal to its power to any target.

Nicol Bolas, Planeswalker

+3: Destroy target noncreature permanent.
−2: Gain control of target creature.
−9: Nicol Bolas, Planeswalker deals 7 damage to target player or planeswalker. That player or that planeswalker's controller discards seven cards, then sacrifices seven permanents of their choice.

Sloppity Bilepiper

Jolly Gutpipes — {2}, {T}, Sacrifice a creature: The next creature spell you cast this turn has cascade. (When you next cast a creature spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Negate

Demon of Catastrophes

As an additional cost to cast this spell, sacrifice a creature.
Flying, trample

Sower of Discord

Flying
As Sower of Discord enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Great Unclean One

Reverberating Summons — At the beginning of your end step, each opponent loses 2 life. Then for each opponent who has less life than you, create a 1/3 black Demon creature token named Plaguebearer of Nurgle.

Deadly Cover-Up

As an additional cost to cast this spell, you may collect evidence 6.
Destroy all creatures. If evidence was collected, exile a card from an opponent's graveyard. Then search its owner's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Mortarion, Daemon Primarch

Flying
Primarch of the Death Guard — At the beginning of your end step, you may pay {X}. If you do, create X 2/2 black Astartes Warrior creature tokens with menace. X can't be greater than the amount of life you lost this turn.

Terminate

Destroy target creature. It can't be regenerated.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Rakshasa Debaser

Whenever Rakshasa Debaser attacks, put target creature card from defending player's graveyard onto the battlefield under your control.
Encore {6}{B}{B} ({6}{B}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Soulflayer

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
If a creature card with flying was exiled with Soulflayer's delve ability, Soulflayer has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, reach, trample, and vigilance.

Dream Devourer

Each nonland card in your hand without foretell has foretell. Its foretell cost is equal to its mana cost reduced by {2}. (During your turn, you may pay {2} and exile it from your hand face down. Cast it on a later turn for its foretell cost.)
Whenever you foretell a card, Dream Devourer gets +2/+0 until end of turn.

Raphael, Fiendish Savior

Flying
Other Demons, Devils, Imps, and Tieflings you control get +1/+1 and have lifelink.
At the beginning of each end step, if a creature card was put into your graveyard from anywhere this turn, create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

Undying Malice

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature of their choice or pays 3 life.

Dimir Signet

Victimize

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

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Forgotten Cave

Forgotten Cave enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Mandate of Abaddon

Choose target creature you control. Destroy all creatures with power less than that creature's power.

Nefarox, Overlord of Grixis

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever Nefarox, Overlord of Grixis attacks alone, defending player sacrifices a creature of their choice.

Mountain

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Embodiment of Agonies

Flying, deathtouch
Embodiment of Agonies enters with a +1/+1 counter on it for each different mana cost among nonland cards in your graveyard. (For example, {2}{B} and {1}{B}{B} are different mana costs.)

Obelisk of Grixis

Kill! Maim! Burn!

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Kill! Maim! Burn! deals 3 damage to target player.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Master of Cruelties

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

Thought Vessel

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

Heralds of Tzeentch

Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Doom Blade

Fellwar Stone

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Rakdos Charm

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

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Withengar Unbound

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Elbrus, the Binding Blade

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, the Binding Blade, then transform it.
Equip {1}

Elbrus, the Binding Blade // Withengar Unbound

Foreboding Ruins

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped.
{T}: Add {B} or {R}.

Orcus, Prince of Undeath

Flying, trample
When Orcus, Prince of Undeath enters, choose one —
• Each other creature gets -X/-X until end of turn. You lose X life.
• Return up to X target creature cards with total mana value X or less from your graveyard to the battlefield. They gain haste until end of turn.

Command Tower

Blood Speaker

At the beginning of your upkeep, you may sacrifice Blood Speaker. If you do, search your library for a Demon card, reveal that card, put it into your hand, then shuffle.
Whenever a Demon enters under your control, return Blood Speaker from your graveyard to your hand.

Where Ancients Tread

Whenever a creature you control with power 5 or greater enters, you may have Where Ancients Tread deal 5 damage to any target.

Sign in Blood

Target player draws two cards and loses 2 life.

Burn

Burn deals 2 damage to any target.
Fuse (You may cast one or both halves of this card from your hand.)

Turn

Until end of turn, target creature loses all abilities and becomes a red Weird with base power and toughness 0/1.
Fuse (You may cast one or both halves of this card from your hand.)

Turn // Burn

Molten Echoes

As Molten Echoes enters, choose a creature type.
Whenever a nontoken creature you control of the chosen type enters, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Pristine Talisman

Urborg, Tomb of Yawgmoth

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

Go for the Throat

Dark Ritual

Sol Ring

Plague Drone

Flying
Rot Fly — If an opponent would gain life, that player loses that much life instead.