The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Ancient Copper Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. You create a number of Treasure tokens equal to the result.

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.

Ancient Silver Dragon

Flying
Whenever this creature 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.

Thornwood Falls

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

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.

Breaching Dragonstorm

When this enchantment enters, exile cards from the top of your library until you exile a nonland card. You may cast it without paying its mana cost if that spell's mana value is 8 or less. If you don't, put that card into your hand.
When a Dragon you control enters, return this enchantment to its owner's hand.

Swiftwater Cliffs

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

Sulfur Falls

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

Dracogenesis

You may cast Dragon spells without paying their mana costs.

Firespitter Whelp

Flying
Whenever you cast a noncreature or Dragon spell, this creature deals 1 damage to each opponent.

Aetherize

Return all attacking creatures to their owner's hand.

Frontier Bivouac

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

Maelstrom of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon spell or an Omen spell.
{4}, {T}, Sacrifice this land: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Have

Dragonspeaker Shaman

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

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.

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.

Frontier Siege

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

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

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.)

Scaled Nurturer

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

Self-Reflection

Create a token that's a copy of target creature you control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mox Jasper

{T}: Add one mana of any color. Activate only if you control a Dragon.

Rampant Growth

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

Nanogene Conversion

Choose target creature you control. Each other creature becomes a copy of that creature until end of turn, except it isn't legendary.

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.

Deceptive Frostkite

Flying
You may have this creature enter as a copy of a creature you control with power 4 or greater, except it's a Dragon in addition to its other types and it has flying.

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.

Don't Have

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."

Terror of Mount Velus

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

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.

Magmatic Hellkite

Flying
When this creature enters, destroy target nonbasic land an opponent controls. Its controller searches their library for a basic land card, puts it onto the battlefield tapped with a stun counter on it, then shuffles. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Skimming Strike

Tap up to one target creature. Draw a card. (Then shuffle this card into its owner's library.)

Dirgur Island Dragon

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Dirgur Island Dragon // Skimming Strike

Farseek

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

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.

Mistrise Village

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn can't be countered.

Mirror Gallery

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.

Ureni, the Song Unending

Flying, protection from white and from black
When Ureni enters, it deals X damage divided as you choose among any number of target creatures and/or planeswalkers your opponents control, where X is the number of lands you control.

Hellkite Whelp

Flying
Whenever this creature attacks, it deals 1 damage to target creature defending player controls.

Acolyte of Bahamut

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

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Mountain

Temur Battlecrier

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

Dragon Sniper

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

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Exotic Orchard

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

Extravagant Replication

At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control.

Dynamic Soar

Put three +1/+1 counters on target creature you control. (Then shuffle this card into its owner's library.)

Whirlwing Stormbrood

Flash
Flying
You may cast sorcery spells and Dragon spells as though they had flash.

Whirlwing Stormbrood // Dynamic Soar

Atarka, World Render

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

Island

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Karplusan Forest

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

Arcane Signet

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

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.

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.

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.

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

Change the Equation

Choose one —
• Counter target spell with mana value 2 or less.
• Counter target red or green spell with mana value 6 or less.

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.

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.

Elemental Bond

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

Rite of the Dragoncaller

Whenever you cast an instant or sorcery spell, create a 5/5 red Dragon creature token with flying.

Lunar Insight

Draw a card for each different mana value among nonland permanents you control.

Heroic Intervention

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

Utvara Hellkite

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

Temur Ascendancy

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

Coil and Catch

Draw three cards, then discard a card. (Then shuffle this card into its owner's library.)

Marang River Regent

Flying
When this creature enters, return up to two other target nonland permanents to their owners' hands.

Marang River Regent // Coil and Catch

Marvin, Murderous Mimic

Marvin has all activated abilities of creatures you control that don't have the same name as this creature.

Sol Ring

Karakyk Guardian

Flying, vigilance, trample
This creature has hexproof if it hasn't dealt damage yet. (It can't be the target of spells or abilities your opponents control.)

Rockfall Vale

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

Mockingbird

Flying
You may have this creature enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast this creature, except it's a Bird in addition to its other types and it has flying.

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.

Sarkhan's Triumph

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

Dragonlord's Servant

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

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.

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.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

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.

Shifting Woodland

This land enters tapped unless you control a Forest.
{T}: Add {G}.
Delirium — {2}{G}{G}: This land becomes a copy of target permanent card in your graveyard until end of turn. Activate only if there are four or more card types among cards in your graveyard.

Rejuvenating Springs

This land enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Panharmonicon

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

Shivan Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

Rapacious Dragon

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

Roiling Dragonstorm

When this enchantment enters, draw two cards, then discard a card.
When a Dragon you control enters, return this enchantment to its owner's hand.

Roost Seek

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Also shuffle this card.)

Sagu Wildling

Flying
When this creature enters, you gain 3 life.

Sagu Wildling // Roost Seek

Forest

Thrakkus the Butcher

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

Rootbound Crag

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

Flush Out

Discard a card. If you do, draw two cards. (Then shuffle this card into its owner's library.)

Stormshriek Feral

Flying, haste
{1}{R}: This creature gets +1/+0 until end of turn.