Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Hovermyr

Guildless Commons

Guildless Commons enters the battlefield tapped.
When Guildless Commons enters the battlefield, return a land you control to its owner's hand.
{T}: Add {C}{C}.

Leaden Myr

Brittle Effigy

{4}, {T}, Exile Brittle Effigy: Exile target creature.

Silverbluff Bridge

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

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Exotic Orchard

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

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.

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.

Transmogrifying Wand

Transmogrifying Wand enters the battlefield with three charge counters on it.
{1}, {T}, Remove a charge counter from Transmogrifying Wand: Destroy target creature. Its controller creates a 2/4 white Ox creature token. Activate only as a sorcery.

Myr Custodian

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

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.

Canoptek Spyder

Flying
Fabricator Claw Array — Whenever another nontoken artifact creature or Vehicle enters the battlefield under your control, draw a card.

Metallic Mimic

As Metallic Mimic enters the battlefield, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters the battlefield with an additional +1/+1 counter on it.

Lodestone Myr

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

Tanglepool Bridge

Tanglepool Bridge enters the battlefield tapped.
Indestructible
{T}: Add {G} or {U}.

Perilous Myr

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

Myr Propagator

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

Duplicant

Imprint — When Duplicant enters the battlefield, you may exile target nontoken creature.
As long as a card exiled with Duplicant is a creature card, Duplicant has the power, toughness, and creature types of the last creature card exiled with Duplicant. It's still a Shapeshifter.

Vault of Whispers

Drossforge Bridge

Drossforge Bridge enters the battlefield tapped.
Indestructible
{T}: Add {B} or {R}.

Myr Kinsmith

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

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Crystal Grotto

When Crystal Grotto enters the battlefield, scry 1.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Bloodline Pretender

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

Energy Refractor

When Energy Refractor enters the battlefield, draw a card.
{2}: Add one mana of any color.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

The Mycosynth Gardens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{X}, {T}: The Mycosynth Gardens becomes a copy of target nontoken artifact you control with mana value X.

Rustvale Bridge

Rustvale Bridge enters the battlefield tapped.
Indestructible
{T}: Add {R} or {W}.

Universal Automaton

Changeling (This card is every creature type.)

Iron Myr

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.

Slagwoods Bridge

Slagwoods Bridge enters the battlefield tapped.
Indestructible
{T}: Add {R} or {G}.

Gold Myr

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.

Myr Battlesphere

When Myr Battlesphere enters the battlefield, 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.

Genesis Chamber

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

Darkmoss Bridge

Darkmoss Bridge enters the battlefield tapped.
Indestructible
{T}: Add {B} or {G}.

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

Skullclamp

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

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Alpha Myr

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

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}.

Myr Welder

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

Cascading Cataracts

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

Palladium Myr

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Myr Scrapling

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

Coretapper

{T}: Put a charge counter on target artifact.
Sacrifice Coretapper: Put two charge counters on target artifact.

Command Tower

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

Myr Enforcer

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

Mistvault Bridge

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

Tree of Tales

Crystal Quarry

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

Myr Servitor

At the beginning of your upkeep, if Myr Servitor is on the battlefield, each player returns all cards named Myr Servitor from their graveyard to the battlefield.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Ugin, the Ineffable

Colorless spells you cast cost {2} less to cast.
+1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand.
−3: Destroy target permanent that's one or more colors.

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.

Sol Ring

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Myr Mindservant

Myr Galvanizer

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

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Prototype Portal

Imprint — When Prototype Portal enters the battlefield, you may exile an artifact card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Myr Retriever

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

Suntouched Myr

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

Perilous Vault

{5}, {T}, Exile Perilous Vault: Exile all nonland permanents.

Moonsilver Key

{1}, {T}, Sacrifice Moonsilver Key: Search your library for an artifact card with a mana ability or a basic land card, reveal it, put it into your hand, then shuffle.

Thornglint Bridge

Thornglint Bridge enters the battlefield tapped.
Indestructible
{T}: Add {G} or {W}.

Great Furnace

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Goldmire Bridge

Goldmire Bridge enters the battlefield tapped.
Indestructible
{T}: Add {W} or {B}.

Mirrorworks

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

Adaptive Automaton

As Adaptive Automaton enters the battlefield, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Alloy Myr

Shimmer Myr

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

Copper 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 Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Razortide Bridge

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

Darksteel Citadel

The Mightstone and Weakstone

When The Mightstone and Weakstone enters the battlefield, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Myr Sire

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

Urza's Workshop

{T}: Add {C}.
Metalcraft — {T}: Add {C} for each Urza's land you control. Activate only if you control three or more artifacts.

Gerrard's Hourglass Pendant

Flash
If a player would begin an extra turn, that player skips that turn instead.
{4}, {T}, Exile Gerrard's Hourglass Pendant: Return to the battlefield tapped all artifact, creature, enchantment, and land cards in your graveyard that were put there from the battlefield this turn.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Ancient Den

Symmetry Matrix

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

Power Depot

Power Depot enters the battlefield 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

Myr Moonvessel

Hall of Tagsin

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Silver Myr

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.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Omega Myr

Spire of Industry

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

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.