Silumgar, the Drifting Death

Flying, hexproof
Whenever a Dragon you control attacks, creatures defending player controls get -1/-1 until end of turn.

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.

Ganax, Astral Hunter

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

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Exotic Orchard

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

Blasphemous Act

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

Mountain

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

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.

Unexpected Windfall

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.")

Forest

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Irrigated Farmland

({T}: Add {W} or {U}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Elvish Mystic

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Jade Orb of Dragonkind

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, it enters with an additional +1/+1 counter on it and gains hexproof until your next turn. (It can't be the target of spells or abilities your opponents control.)

Arcane Signet

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

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Clarion Conqueror

Flying
Activated abilities of artifacts, creatures, and planeswalkers can't be activated.

Counterspell

Refute

Counter target spell. Draw a card, then discard a card.

Carnelian Orb of Dragonkind

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

Patron of the Arts

When this creature enters or dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Kolaghan, the Storm's Fury

Flying
Whenever a Dragon you control attacks, creatures you control get +1/+0 until end of turn.
Dash {3}{B}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Scattered Groves

({T}: Add {G} or {W}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Atarka, World Render

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

Island

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

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 this card from your graveyard to your hand.

Scourge of Valkas

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

Goldspan Dragon

Flying, haste
Whenever this creature 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."

Game Trail

As this land enters, you may reveal a Mountain or Forest card from your hand. If you don't, this land enters tapped.
{T}: Add {R} or {G}.

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Tiamat

Flying
When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Boneyard Scourge

Flying
Whenever a Dragon you control dies while this card is in your graveyard, you may pay {1}{B}. If you do, return this card from your graveyard to the battlefield.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Dragonspeaker Shaman

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

Lapis Orb of Dragonkind

{T}: Add {U}. When you spend this mana to cast a Dragon creature spell, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Destructor Dragon

Flying
When this creature dies, destroy target noncreature permanent.

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Dromoka, the Eternal

Flying
Whenever a Dragon you control attacks, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)

Swamp

Savage Ventmaw

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

Broodmate Dragon

Flying
When this creature enters, create a 4/4 red Dragon creature token with flying.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Bladewing the Risen

Flying
When Bladewing enters, you may return target Dragon permanent card from your graveyard to the battlefield.
{B}{R}: Dragon creatures get +1/+1 until end of turn.

Exude Toxin

Each non-Dragon creature gets -X/-X until end of turn. (Then shuffle this card into its owner's library.)

Scavenger Regent

Scavenger Regent // Exude Toxin

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Plains

Ojutai, Soul of Winter

Flying, vigilance
Whenever a Dragon you control attacks, tap target nonland permanent an opponent controls. That permanent doesn't untap during its controller's next untap step.

Temple of Abandon

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {G}.

Return from the Wilds

Choose two —
• Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
• Create a 1/1 white Human creature token.
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

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 this land: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Scalelord Reckoner

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, destroy target nonland permanent that player controls.

Evolving Wilds

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

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Ugin, the Spirit Dragon

+2: Ugin deals 3 damage to any target.
−X: Exile each permanent with mana value X or less that's one or more colors.
−10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.

Rampant Growth

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

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon you control enters, you may have Sarkhan become a copy of it until end of turn, except its name is Sarkhan, Soul Aflame and it's legendary in addition to its other types.

Temple of the Dragon Queen

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

Dragon Tempest

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

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Command Tower

Dragonstorm Globe

Each Dragon you control enters with an additional +1/+1 counter on it.
{T}: Add one mana of any color.

Ramos, Dragon Engine

Flying
Whenever you cast a spell, put a +1/+1 counter on Ramos for each of that spell's colors.
Remove five +1/+1 counters from Ramos: Add {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}. Activate only once each turn.

Grow from the Ashes

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card, put it onto the battlefield, then shuffle. If this spell was kicked, instead search your library for two basic land cards, put them onto the battlefield, then shuffle.

Geothermal Bog

({T}: Add {B} or {R}.)
This land enters tapped.

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.

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Thunderbreak Regent

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

Rattleclaw Mystic

{T}: Add {G}, {U}, or {R}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, add {G}{U}{R}.

Guttural Response

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Sivitri, Dragon Master

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.
−3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.
−7: Destroy all non-Dragon creatures.
Sivitri, Dragon Master can be your commander.

Rith, Liberated Primeval

Flying, ward {2}
Other Dragons you control have ward {2}.
At the beginning of your end step, if a creature or planeswalker an opponent controlled was dealt excess damage this turn, create a 4/4 red Dragon creature token with flying.

Sol Ring

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Temple of Plenty

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {W}.

Scion of the Ur-Dragon

Flying
{2}: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Dragonlord's Servant

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

Deathbringer Regent

Flying
When this creature enters, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Fearsome Awakening

Return target creature card from your graveyard to the battlefield. If it's a Dragon, put two +1/+1 counters on it.

Rivaz of the Claw

Menace
{T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon creature spells.
Once during each of your turns, you may cast a Dragon creature spell from your graveyard.
Whenever you cast a Dragon creature spell from your graveyard, it gains "When this creature dies, exile it."

Primevals' Glorious Rebirth

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Return all legendary permanent cards from your graveyard to the battlefield.

Terramorphic Expanse

Sarkhan's Triumph

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

Sarkhan Unbroken

+1: Draw a card, then add one mana of any color.
−2: Create a 4/4 red Dragon creature token with flying.
−8: Search your library for any number of Dragon creature cards, put them onto the battlefield, then shuffle.

Fellwar Stone

Scaled Nurturer

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

Chilling Screech

Counter target spell with mana value 2 or less. (Then shuffle this card into its owner's library.)

Runescale Stormbrood

Flying
Whenever you cast a noncreature spell or a Dragon spell, this creature gets +2/+0 until end of turn.

Runescale Stormbrood // Chilling Screech

Rugged Highlands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {G}.

Temple of Triumph

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {W}.

Negate

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.