Commander's Sphere

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

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Battle Hymn

Arcane Signet

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

Smoke Spirits' Aid

For each of up to X target creatures, create a red Aura enchantment token named Smoke Blessing attached to that creature. Those tokens have enchant creature and "When enchanted creature dies, it deals 1 damage to its controller and you create a Treasure token."

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.")

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"

Blasphemous Act

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

Embrace the Unknown

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Bonfire of the Damned

Bonfire of the Damned deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.
Miracle {X}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

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.

The Great Work

(As this Saga enters and after your draw step, add a lore counter.)
I — This Saga deals 3 damage to target opponent and each creature they control.
II — Create three Treasure tokens.
III — Until end of turn, you may cast instant and sorcery spells from any graveyard. If a spell cast this way would be put into a graveyard, exile it instead. Exile this Saga, then return it to the battlefield (front face up).

Urabrask

First strike
Whenever you cast an instant or sorcery spell, Urabrask deals 1 damage to target opponent. Add {R}.
{R}: Exile Urabrask, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery and only if you've cast three or more instant and/or sorcery spells this turn.

Urabrask // The Great Work

Crackling Spellslinger

Flash
When this creature enters, if you cast it, the next instant or sorcery spell you cast this turn has storm. (When you cast that spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Tectonic Reformation

Each land card in your hand has cycling {R}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Mountain

Ashling, Flame Dancer

You don't lose unspent red mana as steps and phases end.
Magecraft — Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Ashling deals 2 damage to each opponent and each creature they control. If it's the third time, add {R}{R}{R}{R}.

Sol Ring

Runaway Steam-Kin

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

Chromatic Sphere

{1}, {T}, Sacrifice this artifact: Add one mana of any color. Draw a card.

Magmatic Insight

As an additional cost to cast this spell, discard a land card.
Draw two cards.

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}.

Finale of Promise

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

Overmaster

The next instant or sorcery spell you cast this turn can't be countered.
Draw a card.

Storm-Kiln Artist

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

Sentinel Tower

Whenever an instant or sorcery spell is cast during your turn, this artifact deals damage to any target equal to 1 plus the number of instant and sorcery spells cast before that spell this turn.

Devil's Play

Devil's Play deals X damage to any target.
Flashback {X}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flaming Gambit

Flaming Gambit deals X damage to target player or planeswalker. That player or that planeswalker's controller may choose a creature they control and have Flaming Gambit deal that damage to it instead.
Flashback {X}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Simian Spirit Guide

Ignorant Bliss

Exile all cards from your hand face down. At the beginning of the next end step, return those cards to your hand, then draw a card.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Silent Gravestone

Cards in graveyards can't be the targets of spells or abilities.
{4}, {T}: Exile this artifact and all cards from all graveyards. Draw a card.

Chromatic Star

{1}, {T}, Sacrifice this artifact: Add one mana of any color.
When this artifact is put into a graveyard from the battlefield, draw a card.

Seething Song

Blood Sun

When this enchantment enters, draw a card.
All lands lose all abilities except mana abilities.

Decaying Time Loop

Discard all the cards in your hand, then draw that many cards.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Detritivore

Detritivore's power and toughness are each equal to the number of nonbasic land cards in your opponents' graveyards.
Suspend X—{X}{3}{R}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{3}{R} and exile it with X 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. It has haste.)
Whenever a time counter is removed from this card while it's exiled, destroy target nonbasic land.

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.

Reroute

Change the target of target activated ability with a single target. (Mana abilities can't be targeted.)
Draw a card.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Storm's Wrath

Storm's Wrath deals 4 damage to each creature and each planeswalker.

Pirate's Pillage

The Rollercrusher Ride

Delirium — If a source you control would deal noncombat damage to a permanent or player while there are four or more card types among cards in your graveyard, it deals double that damage instead.
When The Rollercrusher Ride enters, it deals X damage to each of up to X target creatures.

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.")

Obstinate Familiar

If you would draw a card, you may skip that draw instead.

Reforge the Soul

Each player discards their hand, then draws seven cards.
Miracle {1}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Crime Novelist

Whenever you sacrifice an artifact, put a +1/+1 counter on this creature and add {R}.

Vexing Bauble

Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice this artifact: Draw a card.

Devastating Dreams

As an additional cost to cast this spell, discard X cards at random.
Each player sacrifices X lands of their choice. Devastating Dreams deals X damage to each creature.

Solfatara

Target player can't play lands this turn.
Draw a card at the beginning of the next turn's upkeep.

Bitter Reunion

When this enchantment enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice this enchantment: Creatures you control gain haste until end of turn.

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.

Cosmos Elixir

At the beginning of your end step, draw a card if your life total is greater than your starting life total. Otherwise, you gain 2 life.

Fall of the Titans

Surge {X}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Fall of the Titans deals X damage to each of up to two targets.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Tormenting Voice

Braid of Fire

Cumulative upkeep—Add {R}. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Humble Defector

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

Unexpected Windfall

Valakut, the Molten Pinnacle

This land enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have this land deal 3 damage to any target.
{T}: Add {R}.

Winds of Change

Each player shuffles the cards from their hand into their library, then draws that many cards.

Xorn

If you would create one or more Treasure tokens, instead create those tokens plus an additional Treasure token.

Wheel of Fate

Suspend 4—{1}{R} (Rather than cast this card from your hand, pay {1}{R} and exile it with four 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.)
Each player discards their hand, then draws seven cards.

Delete

Delete deals X damage to each nonartifact creature and each player.

The First Eruption

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga deals 1 damage to each creature without flying.
II — Add {R}{R}.
III — Sacrifice a Mountain. If you do, this Saga deals 3 damage to each creature.

Turf Wound

Target player can't play lands this turn.
Draw a card.

Anger of the Gods

Anger of the Gods deals 3 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Pyretic Ritual

Spiteful Banditry

When this enchantment enters, it deals X damage to each creature.
Whenever one or more creatures your opponents control die, you create a Treasure token. This ability triggers only once each turn.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.