Gruul Guildgate

Gruul Guildgate enters the battlefield tapped.
{T}: Add {R} or {G}.

Myr Adapter

Myr Adapter gets +1/+1 for each Equipment attached to it.

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 Propagator

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

Counterspell

Gold Myr

Arcane Signet

{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.

Swords to Plowshares

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

Gruul Signet

Myr Retriever

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

Azorius Signet

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

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.

Azorius Guildgate

Azorius Guildgate enters the battlefield tapped.
{T}: Add {W} or {U}.

Forest

Shimmer Myr

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

Murder

Sol Ring

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.

Alloy Myr

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Command Tower

Lodestone Myr

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

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

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.

Myr Enforcer

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

Myr Sire

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

Brass Squire

{T}: Attach target Equipment you control to target creature you control.

Negate

Izzet Guildgate

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

Swamp

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.

Selesnya Signet

Myr Scrapling

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

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}.

Mountain

Silver Myr

Reliquary Tower

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

Gateway Plaza

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

Izzet Signet

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.

Rakdos Signet

Nevinyrral's Disk

Nevinyrral's Disk enters the battlefield tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

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.)

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Orzhov Signet

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.)

Dimir Guildgate

Dimir Guildgate enters the battlefield tapped.
{T}: Add {U} or {B}.

Iron Myr

Selesnya Guildgate

Selesnya Guildgate enters the battlefield tapped.
{T}: Add {G} or {W}.

Boros Guildgate

Boros Guildgate enters the battlefield tapped.
{T}: Add {R} 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.

Myr Prototype

At the beginning of your upkeep, put a +1/+1 counter on Myr Prototype.
Myr Prototype can't attack or block unless you pay {1} for each +1/+1 counter on it.

Island

Myr Superion

Spend only mana produced by creatures to cast this spell.

Golgari Signet

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.

Palladium Myr

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Unwinding Clock

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

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.

Myr Welder

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

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.

Hovermyr

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.

Boros Signet

Copper Myr

Myr Galvanizer

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

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.

Golem's Heart

Whenever a player casts an artifact spell, you may gain 1 life.

Golgari Guildgate

Golgari Guildgate enters the battlefield tapped.
{T}: Add {B} or {G}.

Myrsmith

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

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.

Leaden Myr

Plains

Perilous Myr

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

Simic Signet

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.