Jegantha, the Wellspring

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Cascading Cataracts

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

Smoldering Marsh

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

Suntouched Myr

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)

Mountain

Murmuring Bosk

({T}: Add {G}.)
As Murmuring Bosk enters, you may reveal a Treefolk card from your hand. If you don't, Murmuring Bosk enters tapped.
{T}: Add {W} or {B}. Murmuring Bosk deals 1 damage to you.

Lightning Greaves

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

Leaden Myr

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Origin Spellbomb

{1}, {T}, Sacrifice Origin Spellbomb: Create a 1/1 colorless Myr artifact creature token.
When Origin Spellbomb is put into a graveyard from the battlefield, you may pay {W}. If you do, draw a card.

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Darkslick Shores

Darkslick Shores enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Sol Ring

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Razorverge Thicket

Razorverge Thicket enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

Commander's Sphere

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

Command Tower

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

Exotic Orchard

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

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}.

Silver Myr

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}.

Urtet, Remnant of Memnarch

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.
At the beginning of combat on your turn, untap each Myr you control.
{W}{U}{B}{R}{G}, {T}: Put three +1/+1 counters on each Myr you control. Activate only during your turn.

Forest

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Swiftwater Cliffs

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

Myr Mindservant

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Myrsmith

Whenever you cast an artifact spell, you may pay {1}. If you do, create a 1/1 colorless Myr artifact creature token.

Spire of Industry

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only if you control an artifact.

Palladium Myr

Iron Myr

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Myr Sire

When Myr Sire dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Copper Myr

Symmetry Matrix

Whenever a creature you control with power equal to its toughness enters, you may pay {1}. If you do, draw a card.

Plains

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Terramorphic Expanse

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

Crystal Quarry

{T}: Add {C}.
{5}, {T}: Add {W}{U}{B}{R}{G}.

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.)

Wind-Scarred Crag

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

Myr Turbine

{T}: Create a 1/1 colorless Myr artifact creature token.
{T}, Tap five untapped Myr you control: Search your library for a Myr creature card, put it onto the battlefield, then shuffle.

Myr Reservoir

{T}: Add {C}{C}. Spend this mana only to cast Myr spells or activate abilities of Myr.
{3}, {T}: Return target Myr card from your graveyard to your hand.

Frontier Bivouac

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

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Patchwork Automaton

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever you cast an artifact spell, put a +1/+1 counter on Patchwork Automaton.

All Will Be One

Whenever you put one or more counters on a permanent or player, All Will Be One deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Myr Propagator

{3}, {T}: Create a token that's a copy of Myr Propagator.

Alloy Myr

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Universal Automaton

Changeling (This card is every creature type.)

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Omega Myr

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Darkwater Catacombs

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Foundry Inspector

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

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.)

Arcane Signet

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Choked Estuary

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

Myr Incubator

{6}, {T}, Sacrifice Myr Incubator: Search your library for any number of artifact cards, exile them, then create that many 1/1 colorless Myr artifact creature tokens. Then shuffle.

Sunken Hollow

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

Island

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Brass Squire

{T}: Attach target Equipment you control to target creature you control.

Scoured Barrens

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

Myr Kinsmith

When Myr Kinsmith enters, you may search your library for a Myr card, reveal it, put it into your hand, then shuffle.

Chromatic Lantern

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

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Swamp

Grand Coliseum

Grand Coliseum enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Grand Coliseum deals 1 damage to you.

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}.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Myr Matrix

Indestructible (Effects that say "destroy" don't destroy this artifact.)
Myr creatures get +1/+1.
{5}: Create a 1/1 colorless Myr artifact creature token.

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Myr Custodian

When Myr Custodian enters, scry 2. Then each opponent may scry 1. (To scry X, a player looks at the top X cards of their library, then puts any number of them on the bottom and the rest on top in any order.)

Dismal Backwater

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

Gold Myr

Jungle Hollow

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

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Alpha Myr

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Research Thief

Flash
Flying
Whenever an artifact creature you control deals combat damage to a player, draw a card.

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {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}.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.