Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Diabolic Revelation

Search your library for up to X cards, put those cards into your hand, then shuffle.

Song of Totentanz

Create X 1/1 black Rat creature tokens with "This creature can't block." Creatures you control gain haste until end of turn.

Blood Vassal

Cabal Pit

{T}: Add {B}. Cabal Pit deals 1 damage to you.
Threshold — {B}, {T}, Sacrifice Cabal Pit: Target creature gets -2/-2 until end of turn. Activate only if seven or more cards are in your graveyard.

Reiterate

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Ramunap Ruins

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{2}{R}{R}, {T}, Sacrifice a Desert: Ramunap Ruins deals 2 damage to each opponent.

Commune with Lava

Exile the top X cards of your library. Until the end of your next turn, you may play those cards.

Dark Ritual

Evolving Wilds

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

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Ricochet Trap

If an opponent cast a blue spell this turn, you may pay {R} rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Barbarian Ring

{T}: Add {R}. Barbarian Ring deals 1 damage to you.
Threshold — {R}, {T}, Sacrifice Barbarian Ring: It deals 2 damage to any target. Activate only if seven or more cards are in your graveyard.

Arcane Signet

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

Reckless Barbarian

Sacrifice Reckless Barbarian: Add {R}{R}.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Mountain

Shire Terrace

{T}: Add {C}.
{1}, {T}, Sacrifice Shire Terrace: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Plunge into Darkness

Choose one —
• Sacrifice any number of creatures. You gain 3 life for each creature sacrificed this way.
• Pay any amount of life, then look at that many cards from the top of your library. Put one of those cards into your hand and exile the rest.
Entwine {B} (Choose both if you pay the entwine cost.)

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Storm King's Thunder

When you next cast an instant or sorcery spell this turn, copy that spell X times. You may choose new targets for the copies.

Skirk Prospector

Final Parting

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

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Priest of Gix

When Priest of Gix enters, add {B}{B}{B}.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Sol Ring

Rowan, Scion of War

Menace
{T}: Spells you cast this turn that are black and/or red cost {X} less to cast, where X is the amount of life you lost this turn. Activate only as a sorcery.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Electrodominance

Electrodominance deals X damage to any target. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Vessel of Volatility

{1}{R}, Sacrifice Vessel of Volatility: Add {R}{R}{R}{R}.

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ifnir Deadlands

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{2}{B}{B}, {T}, Sacrifice a Desert: Put two -1/-1 counters on target creature an opponent controls. Activate only as a sorcery.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

March of Reckless Joy

As an additional cost to cast this spell, you may exile any number of red cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Exile the top X cards of your library. You may play up to two of those cards until the end of your next turn.

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 artifact: Add one mana of any color.")

Blood Pet

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 artifact: Add one mana of any color.")

Damnable Pact

Target player draws X cards and loses X life.

Ambition's Cost

You draw three cards and you lose 3 life.

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Their Number Is Legion

Create X tapped 2/2 black Necron Warrior artifact creature tokens, then you gain life equal to the number of artifacts you control. Exile Their Number Is Legion.
You may cast Their Number Is Legion from your graveyard.

Treasonous Ogre

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Pay 3 life: Add {R}.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Explosive Welcome

Explosive Welcome deals 5 damage to any target and 3 damage to any other target. Add {R}{R}{R}.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Night's Whisper

Coveted Prize

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
Search your library for a card, put it into your hand, then shuffle. If you have a full party, you may cast a spell with mana value 4 or less from your hand without paying its mana cost.

Finale of Eternity

Destroy up to three target creatures with toughness X or less. If X is 10 or more, return all creature cards from your graveyard to the battlefield.

Descent into Avernus

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

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Path of the Pyromancer

Discard all the cards in your hand. Add {R} for each card discarded this way, then draw that many cards plus one.
Will of the Planeswalkers — Starting with you, each player votes for planeswalk or chaos. If planeswalk gets more votes, planeswalk. If chaos gets more votes or the vote is tied, chaos ensues.

Infernal Plunge

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

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Strike It Rich

Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Rocky Tar Pit

Rocky Tar Pit enters tapped.
{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Terramorphic Expanse

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

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Tendrils of Agony

Target player loses 2 life and you gain 2 life.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Increasing Ambition

Search your library for a card and put that card into your hand. If this spell was cast from a graveyard, instead search your library for two cards and put those cards into your hand. Then shuffle.
Flashback {7}{B} (You may cast this card from your graveyard for its flashback cost. Then exile 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.)

Arco-Flagellant

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Arco-Flagellant can't block.
Endurant — Pay 3 life: Arco-Flagellant gains indestructible until end of turn.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Priest of Urabrask

When Priest of Urabrask enters, add {R}{R}{R}.

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.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Seething Song

Diamond Lion

{T}, Discard your hand, Sacrifice Diamond Lion: Add three mana of any one color. Activate only as an instant.