Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Mana Geyser

Add {R} for each tapped land your opponents control.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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

Silver Shroud Costume

Flash
When this Equipment enters, attach it to target creature you control. That creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
Equipped creature can't be blocked.
Equip {3}

Artist's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever you cast a noncreature spell, you may discard a card. If you do, draw a card.
{2}{R}: Level 2
Noncreature spells you cast cost {1} less to cast.
{2}{R}: Level 3
If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Backdraft Hellkite

Flying
Whenever this creature attacks, each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Firebending Student

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Firebending X, where X is this creature's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)

Red Elemental Blast

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

Demand Answers

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

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.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Inferno of the Star Mounts

This spell can't be countered.
Flying, haste
{R}: Inferno of the Star Mounts gets +1/+0 until end of turn. When its power becomes 20 this way, it deals 20 damage to any target.

Stun

Target creature can't block this turn.
Draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Overmaster

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

Haste Magic

Target creature gets +3/+1 and gains haste until end of turn. Exile the top card of your library. You may play it until your next end step.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Ghitu Firebreathing

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.
{R}: Return this Aura to its owner's hand.

Mysterious Stranger

Flash
When this creature enters, for each graveyard with an instant or sorcery card in it, exile target instant or sorcery card from that graveyard. If two or more cards are exiled this way, choose one of them at random and copy it. You may cast the copy without paying its mana cost.

Electro, Assaulting Battery

Flying
You don't lose unspent red mana as steps and phases end.
Whenever you cast an instant or sorcery spell, add {R}.
When Electro leaves the battlefield, you may pay {X}. When you do, he deals X damage to target player.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When this creature dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

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.

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.")

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.)

Electrostatic Bolt

Electrostatic Bolt deals 2 damage to target creature. If it's an artifact creature, Electrostatic Bolt deals 4 damage to it instead.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Shock

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.

Great Train Heist

Spree (Choose one or more additional costs.)
+ {2}{R} — Untap all creatures you control. If it's your combat phase, there is an additional combat phase after this phase.
+ {2} — Creatures you control get +1/+0 and gain first strike until end of turn.
+ {R} — Choose target opponent. Whenever a creature you control deals combat damage to that player this turn, create a tapped Treasure token.

Mountain

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.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Thrill of Possibility

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

Deserter's Disciple

{T}: Another target creature you control with power 2 or less can't be blocked this turn.

Avatar Roku, Firebender

Whenever a player attacks, add six {R}. Until end of combat, you don't lose this mana as steps end.
{R}{R}{R}: Target creature gets +3/+0 until end of turn.

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

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.

Seething Song

Unexpected Windfall

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Will of the Jeskai

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Each player may discard their hand and draw five cards.
• Each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

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.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Tome of Legends

This artifact enters with a page counter on it.
Whenever your commander enters or attacks, put a page counter on this artifact.
{1}, {T}, Remove a page counter from this artifact: Draw a card.

Sol Ring

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Rose, Cutthroat Raider

First strike
Raid — At end of combat on your turn, if you attacked this turn, create a Junk token for each opponent you attacked. (It's an artifact with "{T}, Sacrifice this token: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")
Whenever you sacrifice a Junk, add {R}.

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.)

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}.

Coruscation Mage

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Zuko, Firebending Master

First strike
Firebending X, where X is the number of experience counters you have. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)
Whenever you cast a spell during combat, you get an experience counter.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Temple of the False God

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

Blasphemous Act

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

Pyroblast

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

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Brotherhood Regalia

Equipped creature has ward {2}, is an Assassin in addition to its other types, and can't be blocked.
Equip legendary creature {1}
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Crimson Wisps

Target creature becomes red and gains haste until end of turn. (It can attack and {T} this turn.)
Draw a card.

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

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.)