Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Myr Landshaper

{T}: Target land becomes an artifact in addition to its other types until end of turn.

Myr Kinsmith

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

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.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Myr Superion

Spend only mana produced by creatures to cast this spell.

Hovermyr

Frogmyr Enforcer

Prototype {3}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

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.

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.

Tomb of the Spirit Dragon

{T}: Add {C}.
{2}, {T}: You gain 1 life for each colorless creature you control.

Copper Myr

Drossforge Bridge

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

Steel Overseer

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

Metallic Mimic

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

Myr Galvanizer

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

Ancient Den

Darkmoss Bridge

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

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.

Myr Sire

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

Bloodline Pretender

Changeling (This card is every creature type.)
As this creature enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on this creature.

Palladium Myr

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Sol Ring

Jhoira, Weatherlight Captain

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

Silver Myr

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.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Myr Retriever

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

Myr Propagator

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

Swords to Plowshares

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

Suntouched Myr

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

Razortide Bridge

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

Buried Ruin

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

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.)

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.

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

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.

Thornglint Bridge

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

Omega 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.

Rustvale Bridge

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

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Goldmire Bridge

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

Iron Myr

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.

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.

Dramatic Reversal

Untap all nonland permanents you control.

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.)

Crystal Skull, Isu Spyglass

You may look at the top card of your library any time.
You may play historic lands and cast historic spells from the top of your library. (Artifacts, legendaries, and Sagas are historic.)
{T}: Add {U}.

Counterspell

Plains

Tanglepool Bridge

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

Blinkmoth Urn

At the beginning of each player's first main phase, if this artifact is untapped, that player adds {C} for each artifact they control.

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Leaden Myr

Darksteel Citadel

Dispatch

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

Myrsmith

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

Alibou, Ancient Witness

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

Foundry Inspector

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

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.

Gold Myr

Thopter Assembly

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

Manifold Key

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

Myr Enforcer

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

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.

Silverbluff Bridge

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

Alpha Myr

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.

Time Sieve

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

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 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.

Unwinding Clock

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

Archway of Innovation

This land enters tapped unless you control an Island.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

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.

Negate

Stoic Rebuttal

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

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.

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.

Shimmer Myr

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

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Seat of the Synod

Mistvault Bridge

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

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.

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.

Vault of Whispers

Arcane Signet

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

Karn, Legacy Reforged

Karn's power and toughness are each equal to the greatest mana value among artifacts you control.
At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.

Urza's Power Plant

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

Great Furnace

Cascading Cataracts

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

Urza's Mine

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