Wild-Magic Sorcerer

The first spell you cast from exile each turn has cascade. (When you cast your first spell from exile, 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.)

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.

Lord Xander, the Collector

When Lord Xander 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.

Inevitable Betrayal

Suspend 3—{1}{U}{U} (Rather than cast this card from your hand, pay {1}{U}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Bloodthirster

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

Mutalith Vortex Beast

Trample
Warp Vortex — When this creature enters, flip a coin for each opponent you have. For each flip you win, draw a card. For each flip you lose, this creature deals 3 damage to that player.

Chaos Defiler

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

Swiftwater Cliffs

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

Lucius the Eternal

Haste
Armour of Shrieking Souls — When Lucius the Eternal dies, exile it and choose target creature an opponent controls. When that creature leaves the battlefield, return this card from exile to the battlefield under its owner's control.

Forgotten Cave

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

Path of Ancestry

This land 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.)

Commander's Sphere

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

Swamp

Sunken Hollow

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

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.

Kill! Maim! Burn!

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

Nalfeshnee

Flying
Whenever you cast a spell from exile, copy it. You may choose new targets for the copy. If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.)

Keeper of Secrets

First strike, haste
Symphony of Pain — Whenever you cast a spell from anywhere other than your hand, this creature deals damage equal to that spell's mana value to target opponent.

Aspiring Champion

Menace
Ruinous Ascension — When this creature deals combat damage to a player, sacrifice it. If you do, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield, then shuffle the rest into your library. If that creature is a Demon, it deals damage equal to its power to each opponent.

Chaos Terminator Lord

Lord of Chaos — At the beginning of combat on your turn, another target creature you control gains double strike until end of turn.

Call Forth the Tempest

Cascade, 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. Then do it again.)
Call Forth the Tempest deals damage to each creature your opponents control equal to the total mana value of other spells you've cast this turn.

Blight Grenade

Destroy target creature.
All creatures get -3/-3 until end of turn.

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."

Bloodcrusher of Khorne

Trample
Devastating Charge — Other creatures you control have trample.

Nicol Bolas, God-Pharaoh

+2: Target opponent exiles cards from the top of their library until they exile a nonland card. Until end of turn, you may cast that card without paying its mana cost.
+1: Each opponent exiles two cards from their hand.
−4: Nicol Bolas deals 7 damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.
−12: Exile each nonland permanent your opponents control.

Let the Galaxy Burn

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.)
Let the Galaxy Burn deals X plus 2 damage to each creature that didn't enter this turn.

Bile Blight

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

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. This artifact deals 1 damage to you.

Forceful Denial

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.)
Counter target spell.

Noise Marine

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.)
Sonic Blaster — When this creature enters, it deals damage equal to the number of spells you've cast this turn to any target.

Island

Abaddon the Despoiler

Trample
Mark of Chaos Ascendant — During your turn, spells you cast from your hand with mana value X or less have cascade, where X is the total amount of life your opponents have lost this turn.

Seeker of Slaanesh

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

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.

Past in Flames

Each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dark Ritual

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.)

Dark Apostle

Gift of Chaos — {3}, {T}: The next noncreature spell you cast this turn has cascade. (When you cast that 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.)

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate this creature.

Blightning

Blightning deals 3 damage to target player or planeswalker. That player or that planeswalker's controller discards two cards.

Deny Reality

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.)
Return target permanent to its owner's hand.

The Horus Heresy

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — For each opponent, gain control of up to one target nonlegendary creature that player controls for as long as this Saga remains on the battlefield.
II — Draw a card for each creature you control but don't own.
III — Starting with you, each player chooses a creature. Destroy each creature chosen this way.

Foreboding Ruins

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

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.)

Exalted Flamer of Tzeentch

Sorcerous Inspiration — At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Fire of Tzeentch — Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

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.

Tzaangor Shaman

Flying
Sorcerous Elixir — Whenever this creature deals combat damage to a player, copy the next instant or sorcery spell you cast this turn when you cast it. You may choose new targets for the copy.

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 this card, all creatures get -2/-2 until end of turn.

Temple of the False God

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

Sol Ring

Magnus the Red

Flying
Unearthly Power — Instant and sorcery spells you cast cost {1} less to cast for each creature token you control.
Blade of Magnus — Whenever Magnus the Red deals combat damage to a player, create a 3/3 red Spawn creature token.

Blasphemous Act

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

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

Wayfarer's Bauble

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

Command Tower

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

Bituminous Blast

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.)
Bituminous Blast deals 4 damage to target creature.

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.

Warstorm Surge

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

Aurora Phoenix

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.)
Whenever you cast a spell with cascade, return this card from your graveyard to your hand.

Mandate of Abaddon

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

Crumbling Necropolis

This land enters tapped.
{T}: Add {U}, {B}, or {R}.

Herald of Slaanesh

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

Brainstorm

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

Pink Horror

Coruscating Flames — Whenever you cast an instant or sorcery spell, this creature deals 2 damage to any target.
Split — When this creature dies, create two 2/2 blue and red Demon Horror creature tokens named Blue Horror with "Whenever you cast an instant or sorcery spell, this token deals 1 damage to any target."

The Lost and the Damned

Whenever a land you control enters from anywhere other than your hand or you cast a spell from anywhere other than your hand, create a 3/3 red Spawn creature token.

Chromatic Lantern

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

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!

Plague Drone

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

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.

Crypt of the Eternals

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

Drach'Nyen

Echo of the First Murder — When Drach'Nyen enters, exile up to one target creature.
Daemon Sword — Equipped creature has menace and gets +X/+0, where X is the exiled card's power.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Hidetsugu and Kairi

Flying
When Hidetsugu and Kairi enters, 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.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. This land deals 1 damage to you.

Mountain

Demonic Dread

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.)
Target creature can't block this turn.