Demanding Dragon

Flying
When Demanding Dragon enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

Flame Sweep

Flame Sweep deals 2 damage to each creature except for creatures you control with flying.

Flameblast Dragon

Flying
Whenever Flameblast Dragon attacks, you may pay {X}{R}. If you do, Flameblast Dragon deals X damage to any target.

Spawn of Thraxes

Flying
When Spawn of Thraxes enters, it deals damage to any target equal to the number of Mountains you control.

Dragonmaster Outcast

At the beginning of your upkeep, if you control six or more lands, create a 5/5 red Dragon creature token with flying.

Dragon's Fire

As an additional cost to cast this spell, you may reveal a Dragon card from your hand or choose a Dragon you control.
Dragon's Fire deals 3 damage to target creature or planeswalker. If you revealed a Dragon card or chose a Dragon as you cast this spell, Dragon's Fire deals damage equal to the power of that card or creature instead.

Lathliss, Dragon Queen

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

Chaos Dragon

Flying, haste
Chaos Dragon attacks each combat if able.
At the beginning of combat on your turn, each player rolls a d20. If one or more opponents had the highest result, Chaos Dragon can't attack those players or planeswalkers they control this combat.

Mountain

Thrill of Possibility

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

Shivan Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this artifact: Add one mana of any color.")

Bogardan Hellkite

Flash
Flying
When Bogardan Hellkite enters, it deals 5 damage divided as you choose among any number of targets.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dragon Hatchling

Flying
{R}: Dragon Hatchling gets +1/+0 until end of turn.

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.

Slumbering Dragon

Flying
Slumbering Dragon can't attack or block unless it has five or more +1/+1 counters on it.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on Slumbering Dragon.

Welding Sparks

Welding Sparks deals X damage to target creature, where X is 3 plus the number of artifacts you control.

Shivan Meteor

Shivan Meteor deals 13 damage to target creature.
Suspend 2—{1}{R}{R} (Rather than cast this card from your hand, you may pay {1}{R}{R} and exile it with two 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.)

Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

Dragonlord's Servant

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

Dragon's Hoard

Whenever a Dragon you control enters, 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.

Warlord's Fury

Creatures you control gain first strike until end of turn.
Draw a card.

Rapacious Dragon

Flying
When this creature enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Demolish

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Volcanic Dragon

Gadrak, the Crown-Scourge

Flying
Gadrak, the Crown-Scourge can't attack unless you control four or more artifacts.
At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Molten Psyche

Each player shuffles the cards from their hand into their library, then draws that many cards.
Metalcraft — If you control three or more artifacts, Molten Psyche deals damage to each opponent equal to the number of cards that player has drawn this turn.

Demand Answers

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

Arcane Signet

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

Sol Ring

Earthquake

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

Blasphemous Act

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

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.

The Elder Dragon War

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — The Elder Dragon War deals 2 damage to each creature and each opponent.
II — Discard any number of cards, then draw that many cards.
III — Create a 4/4 red Dragon creature token with flying.

Where Ancients Tread

Whenever a creature you control with power 5 or greater enters, you may have Where Ancients Tread deal 5 damage to any target.

Skyship Stalker

Flying
{R}: Skyship Stalker gets +1/+0 until end of turn.
{R}: Skyship Stalker gains first strike until end of turn.
{R}: Skyship Stalker gains haste until end of turn.

Battle Hymn

There and Back Again

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Up to one target creature can't block for as long as you control There and Back Again. The Ring tempts you.
II — Search your library for a Mountain card, put it onto the battlefield, then shuffle.
III — Create Smaug, a legendary 6/6 red Dragon creature token with flying, haste, and "When this creature dies, create fourteen Treasure tokens."

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.

Red Dragon

Flying
Fire Breath — When Red Dragon enters, it deals 4 damage to each opponent.

Hoarding Dragon

Flying
When this creature enters, you may search your library for an artifact card, exile it, then shuffle.
When this creature dies, you may put the exiled card into its owner's hand.

Stormbreath Dragon

Flying, haste, protection from white
{5}{R}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Stormbreath Dragon becomes monstrous, it deals damage to each opponent equal to the number of cards in that player's hand.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Utvara Hellkite

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

Furious Rise

At the beginning of your end step, if you control a creature with power 4 or greater, exile the top card of your library. You may play that card until you exile another card with Furious Rise.

Renegade Tactics

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

Ganax, Astral Hunter

Flying
Whenever Ganax, Astral Hunter or another Dragon you control enters, 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.)

Fledgling Dragon

Flying
Threshold — As long as seven or more cards are in your graveyard, Fledgling Dragon gets +3/+3 and has "{R}: Fledgling Dragon gets +1/+0 until end of turn."

Hellkite Charger

Flying, haste
Whenever Hellkite Charger attacks, you may pay {5}{R}{R}. If you do, untap all attacking creatures and after this phase, there is an additional combat phase.

Dragonspeaker Shaman

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

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Opportunistic Dragon

Flying
When Opportunistic Dragon enters, choose target Human or artifact an opponent controls. For as long as Opportunistic Dragon remains on the battlefield, gain control of that permanent, it loses all abilities, and it can't attack or block.

Sparktongue Dragon

Flying
When Sparktongue Dragon enters, you may pay {2}{R}. When you do, it deals 3 damage to any target.

Rolling Temblor

Rolling Temblor deals 2 damage to each creature without flying.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Brimstone Volley

Brimstone Volley deals 3 damage to any target.
Morbid — Brimstone Volley deals 5 damage instead if a creature died this turn.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Dragon Whelp

Flying
{R}: Dragon Whelp gets +1/+0 until end of turn. If this ability has been activated four or more times this turn, sacrifice Dragon Whelp at the beginning of the next end step.

Tyrant's Familiar

Flying, haste
Lieutenant — As long as you control your commander, Tyrant's Familiar gets +2/+2 and has "Whenever Tyrant's Familiar attacks, it deals 7 damage to target creature defending player controls."

Torch Fiend

{R}, Sacrifice Torch Fiend: Destroy target artifact.

Cleaver Riot

Creatures you control gain double strike until end of turn. (They deal both first-strike and regular combat damage.)

Wild Guess

Crucible of Fire

Carnelian Orb of Dragonkind

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