Mirrodin Besieged

As this enchantment enters, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

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.

Kodama's Reach

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.

Hovermyr

Sarcomite Myr

{2}: This creature gains flying until end of turn.
{2}, Sacrifice this creature: Draw a card.

Rustvale Bridge

This land enters tapped.
Indestructible
{T}: Add {R} or {W}.

Tanglepool Bridge

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

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Darksteel Myr

Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)

Inga and Esika

Creatures you control have vigilance and "{T}: Add one mana of any color. Spend this mana only to cast a creature spell."
Whenever you cast a creature spell, if three or more mana from creatures was spent to cast it, draw a card.

Stoic Rebuttal

Metalcraft — This spell costs {1} less to cast if you control three or more artifacts.
Counter target spell.

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.

Drossforge Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {R}.

Great Furnace

Island

Genesis Chamber

Whenever a nontoken creature enters, if this artifact is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Copper Myr

Omega Myr

Leaden Myr

Myr Enforcer

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

Reflections of Littjara

As this enchantment enters, 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.)

Thoughtcast

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

Frantic Salvage

Put any number of target artifact cards from your graveyard on top of your library.
Draw a card.

Command Tower

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

Cultivate

Darkmoss Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {G}.

Counterspell

Alpha Myr

Etchings of the Chosen

As this enchantment enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{1}, Sacrifice a creature of the chosen type: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Patriar's Seal

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

Myr Scrapling

Sacrifice this creature: Put a +1/+1 counter on target creature.

Thornglint Bridge

This land enters tapped.
Indestructible
{T}: Add {G} or {W}.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Tempered Steel

Artifact creatures you control get +2/+2.

Myr Kinsmith

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

Myr Custodian

When this creature 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.)

Myrsmith

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

Gold Myr

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 this creature becomes blocked, it gets +2/+2 until end of turn.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Wake the Past

Return all artifact cards from your graveyard to the battlefield. They gain haste until end of turn.

Silver Myr

Glimmervoid

At the beginning of the end step, if you control no artifacts, sacrifice this land.
{T}: Add one mana of any color.

Goldmire Bridge

This land enters tapped.
Indestructible
{T}: Add {W} or {B}.

Parasitic Implant

Enchant creature
At the beginning of your upkeep, enchanted creature's controller sacrifices it and you create a 1/1 colorless Phyrexian Myr artifact creature token.

Myr Galvanizer

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

Myr Superion

Spend only mana produced by creatures to cast this spell.

Swamp

Organic Extinction

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Destroy all nonartifact creatures.

Silverbluff Bridge

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

Palladium Myr

Razortide Bridge

This land enters tapped.
Indestructible
{T}: Add {W} or {U}.

Chromatic Lantern

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

Foundry Inspector

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

Power Depot

This land enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Suntouched Myr

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

March of Progress

Choose target artifact creature you control. For each creature chosen this way, create a token that's a copy of it.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change its text by replacing all instances of "target" with "each.")

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

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.

Holy Frazzle-Cannon

Whenever equipped creature attacks, put a +1/+1 counter on that creature and each other creature you control that shares a creature type with it.
Equip {1}

Invasion of New Capenna

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, you may sacrifice an artifact or creature. When you do, exile target artifact or creature an opponent controls.

Invasion of New Capenna // Holy Frazzle-Cannon

Slagwoods Bridge

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

Seat of the Synod

Mountain

Ancient Den

Darksteel Monolith

Indestructible
Once each turn, you may pay {0} rather than pay the mana cost for a colorless spell you cast from your hand.

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.

Arcane Signet

Plains

Perilous Myr

When this creature dies, it deals 2 damage to any target.

Iron Myr

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Tree of Tales

Myr Quadropod

{3}: Switch this creature's power and toughness until end of turn.

Myr Propagator

{3}, {T}: Create a token that's a copy of this creature.

Myr Sire

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

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.

Spire of Industry

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

Mistvault Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {B}.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Master's Call

Create two 1/1 colorless Myr artifact creature tokens.

Forest

Parcel Myr

{2}, Sacrifice this creature: Draw a card.

Alloy Myr

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Myr Battlesphere

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