Frontier Siege

As Frontier Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of each of your main phases, add {G}{G}.
• Dragons — Whenever a creature with flying enters the battlefield under your control, you may have it fight target creature you don't control.

Island

Jade Orb of Dragonkind

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, it enters the battlefield 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.)

Carnelian Orb of Dragonkind

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

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Sakura-Tribe Elder

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

Dragonlord's Servant

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

Magmaquake

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

Juvenile Mist Dragon

Flying
Confounding Clouds — When Juvenile Mist Dragon enters the battlefield, 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.

Demanding Dragon

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

Blur

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

Displace

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

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.

Scaled Nurturer

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

Forest

Thrakkus the Butcher

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

Rampant Growth

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

Dragonspeaker Shaman

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

Reflections of Littjara

As Reflections of Littjara enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Zoological Study

Mill five cards, then return a creature card milled this way to your hand. (Then exile this card. You may cast the artifact later from exile.)

Monster Manual

{1}{G}, {T}: You may put a creature card from your hand onto the battlefield.

Monster Manual // Zoological Study

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

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.

Acolyte of Bahamut

Commander creatures you own have "The first Dragon spell you cast each turn costs {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 of your library and the rest on top in any order.)

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Rapacious Dragon

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

Cinder Glade

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

Reckless Barbarian

Sacrifice Reckless Barbarian: Add {R}{R}.

Temple of Abandon

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

Command Tower

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

Spit Flame

Spit Flame deals 4 damage to target creature.
Whenever a Dragon enters the battlefield under your control, you may pay {R}. If you do, return Spit Flame from your graveyard to your hand.

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.

Farseek

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

Arcane Signet

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.

Dragonborn Looter

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

Ghostly Flicker

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

Earthquake

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

Meneldor, Swift Savior

Flying
Whenever Meneldor, Swift Savior deals combat damage to a player, exile up to one target creature you own, then return it to the battlefield under your control.

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.

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.

Tangled Islet

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

Patron of the Arts

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

Breath Weapon

Breath Weapon deals 2 damage to each non-Dragon creature.

Aether Gale

Return six target nonland permanents to their owners' hands.

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

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.)

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.)

Temple of Mystery

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

Temple of Epiphany

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

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Crucible of Fire

Kodama's Reach

Negate

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or haste.)

Miirym, Sentinel Wyrm

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

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

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

Panharmonicon

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

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.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Evolving Wilds

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

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

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.

Skanos Dragonheart

Whenever Skanos Dragonheart attacks, it gets +X/+X until end of turn, where X is the greatest power among other Dragons you control and Dragon cards in your graveyard.
Choose a Background (You can have a Background as a second commander.)

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon enters the battlefield under your control, you may have Sarkhan, Soul Aflame 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.

Sol Ring

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Mountain

Atarka, World Render

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

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Frontier Bivouac

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

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.

Shower of Arrows

Destroy target artifact, enchantment, or creature with flying. Scry 1.

Explore the Underdark

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.
You take the initiative.