Arcane Signet

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

Winter Moon

Players can't untap more than one nonbasic land during their untap steps.

Volcanic Fissure

As Volcanic Fissure enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Sundering Eruption

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle. Creatures without flying can't block this turn.

Sundering Eruption // Volcanic Fissure

Mountain

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.

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Hell to Pay

Hell to Pay deals X damage to target creature. Create a number of tapped Treasure tokens equal to the amount of excess damage dealt to that creature this way.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, Scytheclaw Raptor deals 4 damage to them.

Gone

Return target creature you don't control to its owner's hand.

Dead

Dead // Gone

Imodane, the Pyrohammer

Whenever an instant or sorcery spell you control that targets only a single creature deals damage to that creature, Imodane deals that much damage to each opponent.

Arena of Glory

Arena of Glory enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert Arena of Glory: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Witchstalker Frenzy

This spell costs {1} less to cast for each creature that attacked this turn.
Witchstalker Frenzy deals 5 damage to target creature.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Ghostfire Slice

Devoid (This card has no color.)
This spell costs {2} less to cast if an opponent controls a multicolored permanent.
Ghostfire Slice deals 4 damage to any target.

Bhaal's Invoker

Scorching Ray — {8}: Bhaal's Invoker deals 4 damage to each opponent.

Chandra, Torch of Defiance

+1: Exile the top card of your library. You may cast that card. If you don't, Chandra, Torch of Defiance deals 2 damage to each opponent.
+1: Add {R}{R}.
−3: Chandra, Torch of Defiance deals 4 damage to target creature.
−7: You get an emblem with "Whenever you cast a spell, this emblem deals 5 damage to any target."

Panicked Altisaur

Reach
{T}: Panicked Altisaur deals 2 damage to each opponent.

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.)

Jaya Ballard, Task Mage

{R}, {T}, Discard a card: Destroy target blue permanent.
{1}{R}, {T}, Discard a card: Jaya Ballard, Task Mage deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.
{5}{R}{R}, {T}, Discard a card: Jaya Ballard deals 6 damage to each creature and each player.

Meltdown

Destroy each artifact with mana value X or less.

Prodigal Pyromancer

{T}: Prodigal Pyromancer deals 1 damage to any target.

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Slice and Dice

Slice and Dice deals 4 damage to each creature.
Cycling {2}{R} ({2}{R}, Discard this card: Draw a card.)
When you cycle Slice and Dice, you may have it deal 1 damage to each creature.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Megaton's Fate

Choose one —
• Disarm — Destroy target artifact. Create four Treasure tokens.
• Detonate — Megaton's Fate deals 8 damage to each creature. Each player gets four rad counters.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Ral and the Implicit Maze

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Ral and the Implicit Maze deals 2 damage to each creature and planeswalker your opponents control.
II — You may discard a card. If you do, exile the top two cards of your library. You may play them until the end of your next turn.
III — Create a Spellgorger Weird token. (It's a {2}{R} 2/2 Weird creature with "Whenever you cast a noncreature spell, put a +1/+1 counter on Spellgorger Weird.")

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Suq'Ata Lancer

Haste
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Unleash Shell

Unleash Shell deals 5 damage to target creature or planeswalker and 2 damage to that permanent's controller.

Molten Gatekeeper

Whenever another creature you control enters, Molten Gatekeeper deals 1 damage to each opponent.
Unearth {R} ({R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Trick Shot

Trick Shot deals 6 damage to target creature and 2 damage to up to one other target creature token.

Caught in the Crossfire

Spree (Choose one or more additional costs.)
+ {1} — Caught in the Crossfire deals 2 damage to each outlaw creature. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
+ {1} — Caught in the Crossfire deals 2 damage to each non-outlaw creature.

Pyroceratops

Trample
Whenever you cast a noncreature spell, put a +1/+1 counter on Pyroceratops.

Terror of the Peaks

Flying
Spells your opponents cast that target Terror of the Peaks cost an additional 3 life to cast.
Whenever another creature you control enters, Terror of the Peaks deals damage equal to that creature's power to any target.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Thunderwave

Roll a d20.
1—9 | Thunderwave deals 3 damage to each creature.
10—19 | You may choose a creature. Thunderwave deals 3 damage to each creature not chosen this way.
20 | Thunderwave deals 6 damage to each creature your opponents control.

Rodeo Pyromancers

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

Livaan, Cultist of Tiamat

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Pyroblast

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

Sol Ring

Unruly Catapult

Defender
{T}: Unruly Catapult deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Unruly Catapult.

Fanged Flames

Devoid (This card has no color.)
Fanged Flames deals 4 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Riddle of Lightning

Choose any target. Scry 3, then reveal the top card of your library. Riddle of Lightning deals damage equal to that card's mana value to that permanent or player.

Lightning Axe

As an additional cost to cast this spell, discard a card or pay {5}.
Lightning Axe deals 5 damage to target creature.

Rift Bolt

Rift Bolt deals 3 damage to any target.
Suspend 1—{R} (Rather than cast this card from your hand, you may pay {R} and exile it with a time counter 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.)

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Mystic Peak

As Mystic Peak enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Pinnacle Monk enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Keldon Halberdier

First strike
Suspend 4—{R} (Rather than cast this card from your hand, you may pay {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. It has haste.)

Skoa, Embermage

When Skoa, Embermage enters, it deals 4 damage to any target.
Grandeur — Discard another card named Skoa, Embermage, Sacrifice two Mountains: Skoa deals 4 damage to any target.

Brotherhood's End

Choose one —
• Brotherhood's End deals 3 damage to each creature and each planeswalker.
• Destroy all artifacts with mana value 3 or less.

Brimstone Roundup

Whenever you cast your second spell each turn, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Plot {2}{R} (You may pay {2}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Thunder Salvo

Thunder Salvo deals X damage to target creature, where X is 2 plus the number of other spells you've cast this turn.

Explosive Derailment

Spree (Choose one or more additional costs.)
+ {2} — Explosive Derailment deals 4 damage to target creature.
+ {2} — Destroy target artifact.

Skullcrack

Players can't gain life this turn. Damage can't be prevented this turn. Skullcrack deals 3 damage to target player or planeswalker.

Blasphemous Act

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

Arid Archway

Arid Archway enters tapped.
When Arid Archway enters, return a land you control to its owner's hand. If another Desert was returned this way, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}{C}.

Blisterspit Gremlin

{1}, {T}: Blisterspit Gremlin deals 1 damage to each opponent.
Whenever you cast a noncreature spell, untap Blisterspit Gremlin.

Skirk Shaman

Skirk Shaman can't be blocked except by artifact creatures and/or red creatures.

Stoke Genius

Discard your hand, then draw two cards. (Then exile this card. You may cast the creature later from exile.)

Hearth Elemental

This spell costs {X} less to cast, where X is the number of cards in your graveyard that are instant cards, sorcery cards, and/or have an Adventure.

Hearth Elemental // Stoke Genius

Bandit's Haul

Whenever you commit a crime, put a loot counter on Bandit's Haul. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
{T}: Add one mana of any color.
{2}, {T}, Remove two loot counters from Bandit's Haul: Draw a card.