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.

Urza's Power Plant

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

Urza's Tower

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

Myr Mindservant

Thopter Assembly

Flying
At the beginning of your upkeep, if you control no Thopters other than Thopter Assembly, return Thopter Assembly to its owner's hand and create five 1/1 colorless Thopter artifact creature tokens with flying.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

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.

Prismite

Slagwoods Bridge

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

Drafna, Founder of Lat-Nam

{1}{U}: Return target artifact you control to its owner's hand.
{3}, {T}: Copy target artifact spell you control. (The copy becomes a token.)

Orzhov Guildgate

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

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Boros Guildgate

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

Martyr's Bond

Whenever Martyr's Bond or another nonland permanent you control is put into a graveyard from the battlefield, each opponent sacrifices a permanent of their choice that shares a card type with it.

Alloy Myr

Great Furnace

Drossforge Bridge

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

Chromatic Lantern

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

Forest

Extruder

Echo {4} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
Sacrifice an artifact: Put a +1/+1 counter on target creature.

Razortide Bridge

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

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.

Darksteel Juggernaut

Indestructible
Darksteel Juggernaut's power and toughness are each equal to the number of artifacts you control.
Darksteel Juggernaut attacks each combat if able.

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}.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

Dimir Guildgate

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

Vault of Whispers

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.

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.)

Lux Cannon

{T}: Put a charge counter on Lux Cannon.
{T}, Remove three charge counters from Lux Cannon: Destroy target permanent.

Darksteel Citadel

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.

Silverbluff Bridge

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

Tree of Tales

Xenograft

As Xenograft enters, choose a creature type.
Each creature you control is the chosen type in addition to its other types.

Darkmoss Bridge

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

March of the Machines

Each noncreature artifact is an artifact creature with power and toughness each equal to its mana value. (Equipment that's a creature can't equip a creature.)

Gruul Guildgate

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

Rustvale Bridge

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

Lodestone Myr

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

Indomitable Archangel

Flying
Metalcraft — Artifacts you control have shroud as long as you control three or more artifacts. (An artifact with shroud can't be the target of spells or abilities.)

Tanglepool Bridge

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

Selesnya Guildgate

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

Myr Propagator

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

Golgari Guildgate

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

Tezzeret, Agent of Bolas

+1: Look at the top five cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
−1: Target artifact becomes an artifact creature with base power and toughness 5/5.
−4: Target player loses X life and you gain X life, where X is twice the number of artifacts you control.

Island

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Palladium Myr

Filigree Angel

Flying
When Filigree Angel enters, you gain 3 life for each artifact you control.

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

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.

Myr Retriever

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

Pentavus

Pentavus enters with five +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Pentavus: Create a 1/1 colorless Pentavite artifact creature token with flying.
{1}, Sacrifice a Pentavite: Put a +1/+1 counter on Pentavus.

Time Sieve

{T}, Sacrifice five artifacts: Take an extra turn after this one.

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.

Adaptive Automaton

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

Mistvault Bridge

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

Maze's End

This land enters tapped.
{T}: Add {C}.
{3}, {T}, Return this land to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Tezzeret, Master of the Bridge

Creature and planeswalker spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)
+2: Tezzeret, Master of the Bridge deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
−3: Return target artifact card from your graveyard to your hand.
−8: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.

Temple of the False God

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

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Goldmire Bridge

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

Plains

Azorius Guildgate

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

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control.
Other artifact creatures you control get +1/+1.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

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.

Coretapper

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

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Sol Ring

Thornglint Bridge

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

Shimmer Myr

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

Mountain

Rakdos Guildgate

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

Planar Cleansing

Ancient Den

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Tezzeret, Master of Metal

+1: Reveal cards from the top of your library until you reveal an artifact card. Put that card into your hand and the rest on the bottom of your library in a random order.
−3: Target opponent loses life equal to the number of artifacts you control.
−8: Gain control of all artifacts and creatures target opponent controls.

Urza's Mine

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

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.

Seat of the Synod

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Etched Monstrosity

Etched Monstrosity enters with five -1/-1 counters on it.
{W}{U}{B}{R}{G}, Remove five -1/-1 counters from Etched Monstrosity: Target player draws three cards.

Myr Scrapling

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

Tezzeret, Artifice Master

+1: Create a 1/1 colorless Thopter artifact creature token with flying.
0: Draw a card. If you control three or more artifacts, draw two cards instead.
−9: You get an emblem with "At the beginning of your end step, search your library for a permanent card, put it onto the battlefield, then shuffle."

Myr Welder

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

Swamp

Ashnod's Altar

Gateway Plaza

Gateway Plaza enters tapped.
When Gateway Plaza enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

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

Myr Galvanizer

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

Urza, Prince of Kroog

Artifact creatures you control get +2/+2.
{6}: Create a token that's a copy of target artifact you control, except it's a 1/1 Soldier creature in addition to its other types.

Mycosynth Golem

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Artifact creature spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Unwinding Clock

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

Tezzeret the Schemer

+1: Create a colorless artifact token named Etherium Cell with "{T}, Sacrifice this artifact: Add one mana of any color."
−2: Target creature gets +X/-X until end of turn, where X is the number of artifacts you control.
−7: You get an emblem with "At the beginning of combat on your turn, target artifact you control becomes an artifact creature with base power and toughness 5/5."