Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain enters the battlefield under your control, this emblem deals 4 damage to any target."

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Dragon Tempest

Whenever a creature with flying enters the battlefield under your control, it gains haste until end of turn.
Whenever a Dragon enters the battlefield under your control, it deals X damage to any target, where X is the number of Dragons you control.

Terror of Mount Velus

Flying, double strike
When Terror of Mount Velus enters the battlefield, creatures you control gain double strike until end of turn.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Gauntlet of Power

As Gauntlet of Power enters the battlefield, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.

Cavern-Hoard Dragon

This spell costs {X} less to cast, where X is the greatest number of artifacts an opponent controls.
Flying, trample, haste
Whenever Cavern-Hoard Dragon deals combat damage to a player, you create a Treasure token for each artifact that player controls.

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Crucible of Fire

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.

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.

Soulbright Flamekin

{2}: Target creature gains trample until end of turn. If this is the third time this ability has resolved this turn, you may add {R}{R}{R}{R}{R}{R}{R}{R}.

Witch's Clinic

{T}: Add {C}.
{2}, {T}: Target commander gains lifelink until end of turn.

Nyx Lotus

Nyx Lotus enters the battlefield tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Leyline Tyrant

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

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Rogue's Passage

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

Rite of Flame

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

Caged Sun

As Caged Sun enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Sarkhan, Fireblood

+1: You may discard a card. If you do, draw a card.
+1: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells.
−7: Create four 5/5 red Dragon creature tokens with flying.

Steel Hellkite

Flying
{2}: Steel Hellkite gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by Steel Hellkite this turn. Activate only once each turn.

Dragonspeaker Shaman

Dragon spells you cast cost {2} less to cast.

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of your postcombat main phase, add {R} for each 1 life your opponents have lost this turn.

Twinferno

Choose one —
• When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn.

Thundermaw Hellkite

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermaw Hellkite enters the battlefield, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Carnelian Orb of Dragonkind

{T}: Add {R}. If that mana is spent on a Dragon creature spell, it gains haste until end of turn.

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Tyrant of Kher Ridges

Flying
When Tyrant of Kher Ridges enters the battlefield, it deals 4 damage to any target.
{R}: Tyrant of Kher Ridges gets +1/+0 until end of turn.

Atsushi, the Blazing Sky

Flying, trample
When Atsushi, the Blazing Sky dies, choose one —
• Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
• Create three Treasure tokens.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon enters the battlefield under your control, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Orb of Dragonkind

{1}, {T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.
{R}, {T}, Sacrifice Orb of Dragonkind: Look at the top seven cards of your library. You may reveal a Dragon card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Arcane Signet

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

Dragonlord's Servant

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

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.")

Glittering Stockpile

{T}: Add {R}. Put a stash counter on Glittering Stockpile.
{T}, Sacrifice Glittering Stockpile: Add X mana of any one color, where X is the number of stash counters on Glittering Stockpile.

Thrill of Possibility

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

Dragon's Hoard

Whenever a Dragon enters the battlefield under your control, put a gold counter on Dragon's Hoard.
{T}, Remove a gold counter from Dragon's Hoard: Draw a card.
{T}: Add one mana of any color.

Shivan Devastator

Flying, haste
Shivan Devastator enters the battlefield with X +1/+1 counters on it.

Extraplanar Lens

Imprint — When Extraplanar Lens enters the battlefield, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Sarkhan's Triumph

Search your library for a Dragon creature card, reveal it, put it into your hand, then shuffle.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, it deals X damage to any target, where X is the number of Dragons you control.
{R}: Scourge of Valkas gets +1/+0 until end of turn.

Heraldic Banner

As Heraldic Banner enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ganax, Astral Hunter

Flying
Whenever Ganax, Astral Hunter or another Dragon enters the battlefield under your control, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Mountain

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.)

Thunderbreak Regent

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, Thunderbreak Regent deals 3 damage to that player.

Balefire Dragon

Flying
Whenever Balefire Dragon deals combat damage to a player, it deals that much damage to each creature that player controls.

Verix Bladewing

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Flying
When Verix Bladewing enters the battlefield, if it was kicked, create Karox Bladewing, a legendary 4/4 red Dragon creature token with flying.

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.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth, Maw of Flames attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Cursed Mirror

{T}: Add {R}.
As Cursed Mirror enters the battlefield, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Blood Moon

Hellkite Tyrant

Flying, trample
Whenever Hellkite Tyrant deals combat damage to a player, gain control of all artifacts that player controls.
At the beginning of your upkeep, if you control twenty or more artifacts, you win the game.

Sceptre of Eternal Glory

{T}: Add one mana of any color.
{T}: Add three mana of any one color. Activate only if you control three or more lands with the same name.

Ruby Medallion

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

Urza's Incubator

As Urza's Incubator enters the battlefield, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Sol Ring

Irencrag Feat

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

Ancient Copper Dragon

Flying
Whenever Ancient Copper Dragon deals combat damage to a player, roll a d20. You create a number of Treasure tokens equal to the result.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Roaming Throne

Ward {2}
As Roaming Throne enters the battlefield, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Simian Spirit Guide

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

Town-Razer Tyrant

Flying
When Town-Razer Tyrant enters the battlefield, target nonbasic land you don't control loses all abilities except mana abilities and gains "At the beginning of your upkeep, this permanent deals 2 damage to you unless you sacrifice it."

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Seething Song

Blast-Furnace Hellkite

Artifact offering (You may cast this spell as though it had flash by sacrificing an artifact and paying the difference in mana costs between this and the sacrificed artifact. Mana cost includes color.)
Flying, double strike
Creatures attacking your opponents have double strike.