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.

Evolving Wilds

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

Slagwoods Bridge

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

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.)

Leaden Myr

Forsaken Monument

Colorless creatures you control get +2/+2.
Whenever you tap a permanent for {C}, add an additional {C}.
Whenever you cast a colorless spell, you gain 2 life.

Exotic Orchard

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

Island

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Myr Sire

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

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.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Command Tower

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

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Palladium Myr

Nomad Outpost

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

Frontier Bivouac

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

Opulent Palace

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

Gold Myr

Forest

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.

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 Enforcer

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

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

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.

Etherium Sculptor

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

Mystic Monastery

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

Goldmire Bridge

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

Myr Kinsmith

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

Silverbluff Bridge

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

Thoughtcast

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

Thornglint Bridge

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

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.

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.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Tanglepool Bridge

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

Crumbling Necropolis

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

Fellwar Stone

Iron Myr

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Myr Scrapling

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

Silver 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.

Drossforge Bridge

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

Sculpting Steel

You may have this artifact enter as a copy of any artifact on the battlefield.

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.

Myr Galvanizer

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

Foundry Inspector

Shimmer Myr

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

Darkmoss Bridge

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

Master's Call

Create two 1/1 colorless Myr artifact creature tokens.

Copper Myr

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Darksteel Myr

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

Arcane Signet

Swamp

Distant Melody

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

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Razortide Bridge

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

Brudiclad, Telchor Engineer

Creature tokens you control have haste.
At the beginning of combat on your turn, create a 2/1 blue Phyrexian Myr artifact creature token. Then you may choose a token you control. If you do, each other token you control becomes a copy of that token.

Arcane Sanctum

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

Commander's Sphere

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

Jhoira, Weatherlight Captain

Whenever you cast a historic spell, draw a card. (Artifacts, legendaries, and Sagas are historic.)

Alloy Myr

Lux Artillery

Whenever you cast an artifact creature spell, it gains sunburst. (It enters with a +1/+1 counter on it for each color of mana spent to cast it.)
At the beginning of your end step, if there are thirty or more counters among artifacts and creatures you control, this artifact deals 10 damage to each opponent.

Mountain

Mistvault Bridge

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

Perilous Myr

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

Myr Propagator

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

Sandsteppe Citadel

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

Swords to Plowshares

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

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Counterspell

Origin Spellbomb

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

Hovermyr

Tempered Steel

Artifact creatures you control get +2/+2.

Lodestone Myr

Trample
Tap an untapped artifact you control: This creature gets +1/+1 until end of turn.

Myr Retriever

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

Myr Welder

Imprint — {T}: Exile target artifact card from a graveyard.
This creature has all activated abilities of all cards exiled with it.

Plains

All Is Dust

Each player sacrifices all permanents they control that are one or more colors.

Enthusiastic Mechanaut

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

Knighted Myr

{2}{W}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on this creature, it gains double strike until end of turn.

Seaside Citadel

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

Savage Lands

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

Wake the Past

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

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.

Jungle Shrine

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

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.

Terramorphic Expanse

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.)

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Rustvale Bridge

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

Myrsmith

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

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.

Myr Incubator

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