Demanding Dragon

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

Psionic Pulse

Counter target noncreature spell. (Then exile this card. You may cast the creature later from exile.)

Sapphire Dragon

Flying
Whenever Sapphire Dragon attacks or blocks, scry 2.

Sapphire Dragon // Psionic Pulse

Aether Gale

Return six target nonland permanents to their owners' hands.

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.

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.

Undercover Operative

You may have Undercover Operative enter as a copy of any creature on the battlefield, except it enters with a shield counter on it if you control that creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Skyline Despot

Flying
When Skyline Despot enters, you become the monarch.
At the beginning of your upkeep, if you're the monarch, create a 5/5 red Dragon creature token with flying.

Temple of the Dragon Queen

As Temple of the Dragon Queen enters, you may reveal a Dragon card from your hand. Temple of the Dragon Queen enters tapped unless you revealed a Dragon card this way or you control a Dragon.
As Temple of the Dragon Queen enters, choose a color.
{T}: Add one mana of the chosen color.

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

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.

Arcane Signet

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

Dragonspeaker Shaman

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

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.)

Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.

Lozhan, Dragons' Legacy

Flying
Whenever you cast an Adventure or Dragon spell, Lozhan, Dragons' Legacy deals damage equal to that spell's mana value to any target that isn't a commander.

Counterspell

Mirror Image

You may have Mirror Image enter as a copy of a creature you control.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Siren's Ruse

Exile target creature you control, then return that card to the battlefield under its owner's control. If a Pirate was exiled this way, draw a card.

Thunder Dragon

Flying
When Thunder Dragon enters, it deals 3 damage to each creature without flying.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Mountain

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Myriad Landscape

Myriad Landscape enters 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.

Earthquake Dragon

This spell costs {X} less to cast, where X is the total mana value of Dragons you control.
Flying, trample
{2}{G}, Sacrifice a land: Return Earthquake Dragon from your graveyard to your hand.

Planar Incision

Exile target artifact or creature, then return it to the battlefield under its owner's control with a +1/+1 counter on it.

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.

Draconic Muralists

When Draconic Muralists dies, you may search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
{T}: Draw a card.

Atarka, World Render

Flying, trample
Whenever a Dragon you control attacks, it gains double strike until end of turn.

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.

Savage Ventmaw

Flying
Whenever Savage Ventmaw attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Island

Tangled Islet

({T}: Add {G} or {U}.)
Tangled Islet enters tapped.

Temple of Epiphany

Temple of Epiphany enters tapped.
When Temple of Epiphany enters, scry 1.
{T}: Add {U} or {R}.

Nimbleclaw Adept

Bigby's Hand — {T}: Untap two other target permanents. Activate only as a sorcery and only once each turn.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Iymrith, Desert Doom

Flying
Iymrith, Desert Doom has ward {4} as long as it's untapped.
Whenever Iymrith deals combat damage to a player, draw a card. Then if you have fewer than three cards in hand, draw cards equal to the difference.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Thrakkus the Butcher

Trample
Whenever Thrakkus the Butcher attacks, double the power of each Dragon you control until end of turn.

Haven of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell.
{2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

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.

Secluded Courtyard

As Secluded Courtyard enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

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.

Niv-Mizzet, Dracogenius

Flying
Whenever Niv-Mizzet, Dracogenius deals damage to a player, you may draw a card.
{U}{R}: Niv-Mizzet, Dracogenius deals 1 damage to any target.

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Backdraft Hellkite

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

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Forest

Firkraag, Cunning Instigator

Flying, haste
Whenever one or more Dragons you control attack an opponent, goad target creature that player controls.
Whenever a creature deals combat damage to one of your opponents, if that creature had to attack this combat, you put a +1/+1 counter on Firkraag, Cunning Instigator and you draw a card.

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon you control enters, 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.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} 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.)

Temple of Abandon

Temple of Abandon enters tapped.
When Temple of Abandon enters, scry 1.
{T}: Add {R} or {G}.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Illusionist's Stratagem

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.
Draw a card.

Red Dragon

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

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Ryusei, the Falling Star

Flying
When Ryusei, the Falling Star dies, it deals 5 damage to each creature without flying.

Scaled Nurturer

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, you gain 2 life.

Terror of Mount Velus

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

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.