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.

Heroic Intervention

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

Lozhan, Dragons' Legacy

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

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Exotic Orchard

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

Atarka, World Render

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

One with the Multiverse

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Rampant Growth

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

Cinder Glade

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

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. This land deals 1 damage to you.

Intet, the Dreamer

Flying
Whenever Intet deals combat damage to a player, you may pay {2}{U}. If you do, exile the top card of your library face down. You may look at that card for as long as it remains exiled. You may play that card without paying its mana cost for as long as Intet remains on the battlefield.

Elemental Bond

Whenever a creature you control with power 3 or greater enters, draw a card.

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on this artifact.
{T}, Remove a gold counter from this artifact: Draw a card.
{T}: Add one mana of any color.

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.

Mountain

Rhythm of the Wild

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

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

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.

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.

Klauth, Unrivaled Ancient

Flying, haste
Whenever Klauth attacks, add X mana in any combination of colors, where X is the total power of attacking creatures. Spend this mana only to cast spells. Until end of turn, you don't lose this mana as steps and phases end.

Blasphemous Act

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

Up the Beanstalk

When this enchantment enters and whenever you cast a spell with mana value 5 or greater, draw a card.

Birds of Paradise

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

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.)

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}.

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.

Growth Spiral

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

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.

Three Visits

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

Evolving Wilds

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

Command Tower

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

Forest

Temur Battlecrier

During your turn, spells you cast cost {1} less to cast for each creature you control with power 4 or greater.

Hinterland Harbor

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

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Rootbound Crag

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

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Hammerhead Tyrant

Flying
Whenever you cast a spell, return up to one target nonland permanent an opponent controls with mana value less than or equal to that spell's mana value to its owner's hand.

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."

Preordain

Scry 2, then draw a card. (To 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.)

Farseek

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

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, 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.)

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Sakura-Tribe Elder

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

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.

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.

Dragonlord's Servant

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

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.

Kodama's Reach

Genesis Ultimatum

Look at the top five cards of your library. Put any number of permanent cards from among them onto the battlefield and the rest into your hand. Exile Genesis Ultimatum.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Encroaching Dragonstorm

When this enchantment enters, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
When a Dragon you control enters, return this enchantment to its owner's hand.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Dragonspeaker Shaman

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

Temur Ascendancy

Creatures you control have haste.
Whenever a creature you control with power 4 or greater enters, you may draw a card.

Path of Ancestry

This land 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.)

Utvara Hellkite

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

Sulfur Falls

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

Nature's Lore

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

Terramorphic Expanse

Thrakkus the Butcher

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

Llanowar Elves

Island

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Maelstrom Wanderer

Creatures you control have haste.
Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Then do it again.)

Terror of the Peaks

Flying
Spells your opponents cast that target this creature cost an additional 3 life to cast.
Whenever another creature you control enters, this creature deals damage equal to that creature's power to any target.

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.)

Broodcaller Scourge

Flying
Whenever one or more Dragons you control deal combat damage to a player, you may put a permanent card with mana value less than or equal to that damage from your hand onto the battlefield.

Carnelian Orb of Dragonkind

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

Thundermane Dragon

Flying
You may look at the top card of your library any time.
You may cast creature spells with power 4 or greater from the top of your library. If you cast a creature spell this way, it gains haste until end of turn.