Have

Renari, Merchant of Marvels

You may cast Dragon spells and artifact spells as though they had flash.
Choose a Background (You can have a Background as a second commander.)

Revolutionary Rebuff

Counter target nonartifact spell unless its controller pays {2}.

Ancient Bronze Dragon

Flying
Whenever Ancient Bronze Dragon deals combat damage to a player, roll a d20. When you do, put X +1/+1 counters on each of up to two target creatures, where X is the result.

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.)

Don't Have

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Ancient Hellkite

Flying
{R}: Ancient Hellkite deals 1 damage to target creature defending player controls. Activate only if Ancient Hellkite is attacking.

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Temple of Abandon

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

Negate

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.

Dissension in the Ranks

Target blocking creature fights another target blocking creature.

Essence Scatter

Herdchaser Dragon

Flying, trample
Megamorph {5}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Herdchaser Dragon is turned face up, put a +1/+1 counter on each other Dragon creature you control.

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.

Silvanus's Invoker

Conjure Elemental — {8}: Untap target land you control. It becomes an 8/8 Elemental creature with trample and haste until end of turn. It's still a land.

Gruul Guildgate

Gruul Guildgate enters tapped.
{T}: Add {R} or {G}.

Ice Over

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.

Urza's Incubator

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

Oceanus Dragon

Flying
When Oceanus Dragon enters, tap target creature an opponent controls. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Getting

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.

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.

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.

You Look Upon the Tarrasque

Choose one —
• Run and Hide — Prevent all combat damage that would be dealt to you and creatures you control this turn.
• Gather Your Courage — Target creature gets +5/+5 and gains indestructible until end of turn. All creatures your opponents control able to block that creature this turn do so.

Dragonborn Looter

{1}, {T}: Draw a card, then discard a card.

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.

Scale Deflection

Put two +1/+1 counters on target creature and untap it. It gains hexproof until end of turn. (Then exile this card. You may cast the creature later from exile.)

Dread Linnorm

Dread Linnorm can't be blocked by creatures with power 3 or less.

Dread Linnorm // Scale Deflection

Minion of the Mighty

Menace
Pack tactics — Whenever Minion of the Mighty attacks, if you attacked with creatures with total power 6 or greater this combat, you may put a Dragon creature card from your hand onto the battlefield tapped and attacking.

Sea Gate

Sea Gate enters tapped.
As Sea Gate enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

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.

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.

Counterspell

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Juvenile Mist Dragon

Flying
Confounding Clouds — When Juvenile Mist Dragon enters, for each opponent, tap up to one target creature that player controls. Each of those creatures doesn't untap during its controller's next untap step.

Island

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

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.)

Acolyte of Bahamut

Commander creatures you own have "The first Dragon spell you cast each turn costs {2} less to cast."

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.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Forest

Arcane Signet

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

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.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.

Mountain

By Force

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Evolving Wilds

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

Woodland Stream

Woodland Stream enters tapped.
{T}: Add {G} or {U}.

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Gond Gate

Gates you control enter untapped.
{T}: Add {C}.
{T}: Add one mana of any color that a Gate you control could produce.

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

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.

Freejam Regent

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
{1}{R}: Freejam Regent gets +2/+0 until end of turn.

Cinder Glade

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

Dragon Cultist

Commander creatures you own have "At the beginning of your end step, if a source you controlled dealt 5 or more damage this turn, create a 4/4 red Dragon creature token with flying."

Utvara Hellkite

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

Cliffgate

Cliffgate enters tapped.
As Cliffgate enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Bathe in Gold

Create a Treasure token. (Then exile this card. You may cast the creature later from exile.)

Young Red Dragon

Young Red Dragon // Bathe in Gold

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.)

Sol Ring

Astral Dragon

Flying
Project Image — When Astral Dragon enters, create two tokens that are copies of target noncreature permanent, except they're 3/3 Dragon creatures in addition to their other types, and they have flying.

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice Bag of Holding: Return all cards exiled with Bag of Holding to their owner's hand.

Sand Augury

Scry 1, then draw a card. (Then exile this card. You may cast the creature later from exile.)

Young Blue Dragon

Young Blue Dragon // Sand Augury

Contradict

Open into Wonder

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

Sarkhan's Rage

Sarkhan's Rage deals 5 damage to any target. If you control no Dragons, Sarkhan's Rage deals 2 damage to you.

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

Mana Geyser

Add {R} for each tapped land your opponents control.

Blasphemous Act

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

Dream Fracture

Counter target spell. Its controller draws a card.
Draw a card.

Cancel

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.

Pseudodragon Familiar

Flying
{2}{U}: Target creature gains flying until end of turn.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Disallow

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Crucible of the Spirit Dragon

{T}: Add {C}.
{1}, {T}: Put a storage counter on Crucible of the Spirit Dragon.
{T}, Remove X storage counters from Crucible of the Spirit Dragon: Add X mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.

Manor Gate

Manor Gate enters tapped.
As Manor Gate enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Sheltered Aerie

Enchant land
Enchanted land has "{T}: Add two mana of any one color."

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

Sword Coast Serpent can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Nimbleclaw Adept

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

Highland Lake

Highland Lake enters tapped.
{T}: Add {U} or {R}.

Scaled Nurturer

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

Plant Tadpoles

Tap X target creatures. They don't untap during their controllers' next untap steps. (Then exile this card. You may cast the creature later from exile.)

Illithid Harvester

Ceremorphosis — When Illithid Harvester enters, turn any number of target tapped nontoken creatures face down. They're 2/2 Horror creatures.

Illithid Harvester // Plant Tadpoles

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

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.

Simic Guildgate

Simic Guildgate enters tapped.
{T}: Add {G} or {U}.

Thrakkus the Butcher

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

Sulfur Falls

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