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 of your library in a random order.)

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Rune-Scarred Demon

Flying
When Rune-Scarred Demon enters the battlefield, search your library for a card, put it into your hand, then shuffle.

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters the battlefield, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Lord Xander, the Collector

When Lord Xander, the Collector enters the battlefield, 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, rounded down.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Bloodthirster

Flying, trample
Whenever Bloodthirster deals combat damage to a player, untap it. After this combat phase, there is an additional combat phase.
Bloodthirster can't attack a player it has already attacked this turn.

Sloppity Bilepiper

Jolly Gutpipes — {2}, {T}, Sacrifice a creature: The next creature spell you cast this turn has cascade. (When you cast your next 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 of your library in a random order.)

Lord of Change

Flying, ward {3}
Architect of Deception — When Lord of Change enters the battlefield, draw three cards.

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.

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters the battlefield tapped.

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.

Liliana's Contract

When Liliana's Contract enters the battlefield, you draw four cards and you lose 4 life.
At the beginning of your upkeep, if you control four or more Demons with different names, you win the game.

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}.

Rakdos, the Showstopper

Flying, trample
When Rakdos, the Showstopper enters the battlefield, flip a coin for each creature that isn't a Demon, Devil, or Imp. Destroy each creature whose coin comes up tails.

Sunken Hollow

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

Seeker of Slaanesh

Haste
Allure of Slaanesh — Each opponent must attack with at least one creature each combat if able.

Chaos Defiler

Trample
Battle Cannon — When Chaos Defiler enters the battlefield or dies, for each opponent, choose a nonland permanent that player controls. Destroy one of them chosen at random.

Hidetsugu and Kairi

Flying
When Hidetsugu and Kairi enters the battlefield, draw three cards, then put two cards from your hand on top of your library in any order.
When Hidetsugu and Kairi dies, exile the top card of your library. Target opponent loses life equal to its mana value. If it's an instant or sorcery card, you may cast it without paying its mana cost.

Nurgle's Rot

Enchant creature an opponent controls
When enchanted creature dies, return Nurgle's Rot to its owner's hand and you create a 1/3 black Demon creature token named Plaguebearer of Nurgle.

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."

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

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!

Promise of Power

Choose one —
• You draw five cards and you lose 5 life.
• Create an X/X black Demon creature token with flying, where X is the number of cards in your hand.
Entwine {4} (Choose both if you pay the entwine cost.)

Exotic Orchard

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

Sol Ring

Rakdos Signet

Rakdos the Defiler

Flying, trample
Whenever Rakdos the Defiler attacks, sacrifice half the non-Demon permanents you control, rounded up.
Whenever Rakdos deals combat damage to a player, that player sacrifices half the non-Demon permanents they control, rounded up.

Demon of Wailing Agonies

Flying
Lieutenant — As long as you control your commander, Demon of Wailing Agonies gets +2/+2 and has "Whenever Demon of Wailing Agonies deals combat damage to a player, that player sacrifices a creature."

Island

Tallyman of Nurgle

Lifelink
The Seven-fold Chant — At the beginning of your end step, if a creature died this turn, you draw a card and you lose 1 life. If seven or more creatures died this turn, instead you draw seven cards and you lose 7 life.

Swamp

Bile Blight

Target creature and all other creatures with the same name as that creature get -3/-3 until end of turn.

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.

Kardur, Doomscourge

When Kardur, Doomscourge enters the battlefield, 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.

Harvester of Souls

Deathtouch
Whenever another nontoken creature dies, you may draw a card.

Don't Have

Orcus, Prince of Undeath

Flying, trample
When Orcus, Prince of Undeath enters the battlefield, 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.

Charcoal Diamond

Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters the battlefield tapped.

Dimir Signet

Kothophed, Soul Hoarder

Flying
Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Command Tower

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

Venomcrawler

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

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.)

Silent-Blade Oni

Ninjutsu {4}{U}{B} ({4}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Silent-Blade Oni deals combat damage to a player, look at that player's hand. You may cast a spell from among those cards without paying its mana cost.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Desecration Demon

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

Conductor of Cacophony

Conductor of Cacophony enters the battlefield with two +1/+1 counters on it.
{B}, Remove a +1/+1 counter from Conductor of Cacophony: It deals 1 damage to each other creature and each player.

The Ruinous Powers

At the beginning of your upkeep, choose an opponent at random. Exile the top card of that player's library. Until end of turn, you may play that card and you may spend mana as though it were mana of any color to cast it. When you cast a spell this way, its owner loses life equal to its mana value.

Bothersome Quasit

Menace
Goaded creatures your opponents control can't block.
Whenever you cast a noncreature spell, goad target creature an opponent controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

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.)

Terramorphic Expanse

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

Dark Ritual

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Ambition's Cost

You draw three cards and you lose 3 life.

Crumbling Necropolis

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

Mountain

Seizan, Perverter of Truth

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

Be'lakor, the Dark Master

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

Rakdos, Lord of Riots

You can't cast this spell 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.

Mark of the Oni

Enchant creature
You control enchanted creature.
At the beginning of the end step, if you control no Demons, sacrifice Mark of the Oni.

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Reaper from the Abyss

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

Herald of Slaanesh

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

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Temple of the False God

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

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle Decree of Pain, all creatures get -2/-2 until end of turn.

Bloodgift Demon

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

Foreboding Ruins

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

Hidetsugu, Devouring Chaos

{B}, Sacrifice a creature: Scry 2.
{2}{R}, {T}: Exile the top card of your library. You may play that card this turn. When you exile a nonland card this way, Hidetsugu, Devouring Chaos deals damage equal to the exiled card's mana value to any target.

Khârn the Betrayer

Berzerker — Khârn the Betrayer attacks or blocks each combat if able.
Sigil of Corruption — When you lose control of Khârn the Betrayer, draw two cards.
The Betrayer — If damage would be dealt to Khârn the Betrayer, prevent that damage and an opponent of your choice gains control of it.

Izzet Signet

Bloodcrusher of Khorne

Trample
Devastating Charge — Other creatures you control have trample.

Plague Drone

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

Mandate of Abaddon

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

Evolving Wilds

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

Balor

Flying
Whenever Balor attacks or dies, choose one or more. Each mode must target a different player.
• Target opponent draws three cards, then discards three cards at random.
• Target opponent sacrifices a nontoken artifact.
• Balor deals damage to target opponent equal to the number of cards in their hand.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

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.