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.

Ancient Den

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.

Darksteel Citadel

Mountain

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.

Reflections of Littjara

As Reflections of Littjara 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.)

Generous Gift

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

Mechtitan Core

{5}, Exile Mechtitan Core and four other artifact creatures and/or Vehicles you control: Create Mechtitan, a legendary 10/10 Construct artifact creature token with flying, vigilance, trample, lifelink, and haste that's all colors. When that token leaves the battlefield, return all cards exiled with Mechtitan Core except Mechtitan Core to the battlefield tapped under their owners' control.
Crew 2

Iron Myr

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Gold Myr

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Forest

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.")

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Jhoira, Weatherlight Captain

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

Thoughtcast

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

Power Depot

Power Depot 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

Foundry Inspector

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

Command Tower

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

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 Knighted Myr, it gains double strike until end of turn.

Copper Myr

Seat of the Synod

Spire of Industry

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

Sol Ring

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.)

Shimmer Dragon

Flying
As long as you control four or more artifacts, Shimmer Dragon has hexproof. (It can't be the target of spells or abilities your opponents control.)
Tap two untapped artifacts you control: Draw a card.

Silver Myr

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

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.

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.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Wake the Past

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

Arcane Signet

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.)

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

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.

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, Lux Artillery deals 10 damage to each opponent.

Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Elven Chorus

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
Creatures you control have "{T}: Add one mana of any color."

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Swords to Plowshares

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

Dramatic Reversal

Untap all nonland permanents you control.

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

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.

Exotic Orchard

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

Steel Overseer

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

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.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Mirrodin Besieged

As Mirrodin Besieged 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.

Vanquisher's Banner

As Vanquisher's Banner 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.

Myr Kinsmith

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

Alibou, Ancient Witness

Other artifact creatures you control have haste.
Whenever one or more artifact creatures you control attack, Alibou, Ancient Witness deals X damage to any target and you scry X, where X is the number of tapped artifacts you control.

Sculpting Steel

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

Distant Melody

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

Myr Retriever

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

Genesis Chamber

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

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Island

Shimmer Myr

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

Thran Dynamo

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Mistvault Bridge

Mistvault Bridge enters tapped.
Indestructible
{T}: Add {U} or {B}.

Alloy Myr

Semblance Anvil

Imprint — When Semblance Anvil enters, you may exile a nonland card from your hand.
Spells you cast that share a card type with the exiled card cost {2} less to cast.

Fellwar Stone

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Vault of Whispers

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Chromatic Lantern

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

Open the Vaults

Return all artifact and enchantment cards from all graveyards to the battlefield under their owners' control. (Auras with nothing to enchant remain in graveyards.)

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.)

Dance of the Manse

Return up to X target artifact and/or non-Aura enchantment cards each with mana value X or less from your graveyard to the battlefield. If X is 6 or more, those permanents are 4/4 creatures in addition to their other types.

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}.

Lightning Greaves

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

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Leaden Myr

Palladium Myr

Skyclave Relic

Kicker {3}
Indestructible
When Skyclave Relic enters, if it was kicked, create two tapped tokens that are copies of Skyclave Relic.
{T}: Add one mana of any color.

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.)

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.

Hovermyr

Tree of Tales

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Myr Galvanizer

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

Myrsmith

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

Great Furnace

Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")