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.

Embodiment of Flame

Whenever a spell you control deals damage, put a flame counter on this creature.
{1}, Remove a flame counter from this creature: Exile the top card of your library. You may play that card this turn.

Flame Channeler

When a spell you control deals damage, transform this creature.

Flame Channeler // Embodiment of Flame

Magma Spray

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

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.)

Pyromancer's Assault

Whenever you cast your second spell each turn, this enchantment deals 2 damage to any target.

Devoted Duelist

Haste
Flurry — Whenever you cast your second spell each turn, this creature deals 1 damage to each opponent.

Letter of Acceptance

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

Hearthborn Battler

Haste
Whenever a player casts their second spell each turn, this creature deals 2 damage to target opponent.

Lunar Frenzy

Target creature you control gets +X/+0 and gains first strike and trample until end of turn.

Mountain

Magnifying Glass

{T}: Add {C}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Hexgold Slash

Hexgold Slash deals 2 damage to target creature. If that creature has toxic, Hexgold Slash deals 4 damage to that creature instead.

Seer's Lantern

{T}: Add {C}.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

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.)

Flame-Blessed Bolt

Flame-Blessed Bolt deals 2 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Skycrash

Destroy target artifact.
Cycling {R} ({R}, Discard this card: Draw a card.)

Honored Heirloom

{T}: Add one mana of any color.
{2}, {T}: Exile target card from a graveyard.

Thrill of Possibility

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Seize the Storm

Create a red Elemental creature token with trample and "This token's power and toughness are each equal to the number of instant and sorcery cards in your graveyard plus the number of cards with flashback you own in exile."
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tavern Brawler

Commander creatures you own have "At the beginning of your upkeep, exile the top card of your library. This creature gets +X/+0 until end of turn, where X is that card's mana value. You may play that card this turn."

Rush of Blood

Target creature gets +X/+0 until end of turn, where X is its power.

Rabid Gnaw

Target creature you control gets +1/+0 until end of turn. Then it deals damage equal to its power to target creature you don't control.

Balduvian Rage

Target attacking creature gets +X/+0 until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Blitzball

{T}: Add one mana of any color.
GOOOOAAAALLL! — {T}, Sacrifice this artifact: Draw two cards. Activate only if an opponent was dealt combat damage by a legendary creature this turn.

Savage Alliance

Escalate {1} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Creatures target player controls gain trample until end of turn.
• Savage Alliance deals 2 damage to target creature.
• Savage Alliance deals 1 damage to each creature target opponent controls.

Surreal Memoir

Return an instant card at random from your graveyard to your hand.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Explosive Derailment

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

Lantern of Revealing

{T}: Add one mana of any color.
{4}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, you may put it on the bottom of your library.

Cait Sith, Fortune Teller

Lucky Slots — At the beginning of combat on your turn, scry 1, then exile the top card of your library. You may play that card this turn. When you exile a card this way, target creature you control gets +X/+0 until end of turn, where X is that card's mana value.

Junktown

{T}: Add {C}.
{4}{R}, {T}, Sacrifice this land: Create three Junk tokens. (They're artifacts with "{T}, Sacrifice this token: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Thermo-Alchemist

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

Shivan Fire

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Shivan Fire deals 2 damage to target creature. If this spell was kicked, it deals 4 damage instead.

Raging Battle Mouse

The second spell you cast each turn costs {1} less to cast.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

Sorceress's Schemes

Return target instant or sorcery card from your graveyard or exiled card with flashback you own to your hand. Add {R}.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Seize Opportunity

Choose one —
• Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
• Up to two target creatures each get +2/+1 until end of turn.

Call the Mountain Chocobo

Search your library for a Mountain card, reveal it, put it into your hand, then shuffle. Create a 2/2 green Bird creature token with "Whenever a land you control enters, this token gets +1/+0 until end of turn."
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tormenting Voice

Scorchmark

Scorchmark deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Breeches, Brazen Plunderer

Menace
Whenever one or more Pirates you control deal damage to your opponents, exile the top card of each of those opponents' libraries. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Partner (You can have two commanders if both have partner.)

Galvanic Relay

Exile the top card of your library. During your next turn, you may play that card.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Teetering Peaks

This land enters tapped.
When this land enters, target creature gets +2/+0 until end of turn.
{T}: Add {R}.

Into the Time Vortex

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.)
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Chainsaw

When this Equipment enters, it deals 3 damage to up to one target creature.
Whenever one or more creatures die, put a rev counter on this Equipment.
Equipped creature gets +X/+0, where X is the number of rev counters on this Equipment.
Equip {3}

Starting Column

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
{T}: Add one mana of any color.
Max speed — {T}, Sacrifice this artifact: Draw two cards, then discard a card.

Faithless Salvaging

Discard a card, then draw a card.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Brambleguard Captain

At the beginning of combat on your turn, target creature you control gets +X/+0 until end of turn, where X is this creature's power.

Equilibrium Adept

When this creature enters, exile the top card of your library. Until the end of your next turn, you may play that card.
Flurry — Whenever you cast your second spell each turn, this creature gains double strike until end of turn.

Fire Prophecy

Fire Prophecy deals 3 damage to target creature. You may put a card from your hand on the bottom of your library. If you do, draw a card.

Looming Spires

This land enters tapped.
When this land enters, target creature gets +1/+1 and gains first strike until end of turn.
{T}: Add {R}.

Outlaws' Fury

Creatures you control get +2/+0 until end of turn. If you control an outlaw, exile the top card of your library. Until the end of your next turn, you may play that card. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Hand of Vecna

At the beginning of combat on your turn, equipped creature or a creature you control named Vecna gets +X/+X until end of turn, where X is the number of cards in your hand.
Equip—Pay 1 life for each card in your hand.
Equip {2}

Earth Tremor

Earth Tremor deals damage to target creature or planeswalker equal to the number of lands you control.

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Kindled Fury

Target creature gets +1/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Runechanter's Pike

Equipped creature has first strike and gets +X/+0, where X is the number of instant and sorcery cards in your graveyard.
Equip {2}

Return the Past

During your turn, each instant and sorcery card in your graveyard has flashback. Its flashback cost is equal to its mana cost.

Staggershock

Staggershock deals 2 damage to any target.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Iron-Fist Pulverizer

Reach
Whenever you cast your second spell each turn, this creature deals 2 damage to target opponent. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Harnesser of Storms

Whenever you cast a noncreature or Otter spell, you may exile the top card of your library. Until end of turn, you may play that card. This ability triggers only once each turn.

Captain Ripley Vance

Whenever you cast your third spell each turn, put a +1/+1 counter on Captain Ripley Vance, then it deals damage equal to its power to any target.

Geistflame Reservoir

Whenever you cast an instant or sorcery spell, put a charge counter on this artifact.
{1}{R}, {T}, Remove any number of charge counters from this artifact: It deals that much damage to any target.
{1}{R}, {T}: Exile the top card of your library. You may play that card this turn.

Spitfire Bastion

(Transforms from Vance's Blasting Cannons.)
{T}: Add {R}.
{2}{R}, {T}: Spitfire Bastion deals 3 damage to any target.

Vance's Blasting Cannons

At the beginning of your upkeep, exile the top card of your library. If it's a nonland card, you may cast that card this turn.
Whenever you cast your third spell in a turn, you may transform Vance's Blasting Cannons.