Herald's Horn

As Herald's Horn enters, 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.

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.

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.

Omega 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.

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

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.

Sol Ring

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.

Karn, Living Legacy

+1: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
−1: Pay any amount of mana. Look at that many cards from the top of your library, then put one of those cards into your hand and the rest on the bottom of your library in a random order.
−7: You get an emblem with "Tap an untapped artifact you control: This emblem deals 1 damage to any target."

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.

Tempered Steel

Artifact creatures you control get +2/+2.

Goldmire Bridge

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

Darksteel Citadel

Vault of Whispers

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.)

Cranial Ram

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+1, where X is the number of artifacts you control.
Equip {2}

Spire of Industry

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

Forest

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}.

Iron Myr

Myr Propagator

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

Razortide Bridge

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

Island

Myr Welder

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

Myr Retriever

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

Slagwoods Bridge

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

Organic Extinction

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Destroy all nonartifact creatures.

Myr Enforcer

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

Myr Custodian

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

Tanglepool Bridge

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

Plains

Scene of the Crime

Scene of the Crime enters tapped.
{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.
{2}, Sacrifice Scene of the Crime: Draw a card.

Padeem, Consul of Innovation

Artifacts you control have hexproof.
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.

Perilous Myr

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

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.

Arcane Signet

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

Myr Galvanizer

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

Three Tree Mascot

Changeling (This card is every creature type.)
{1}: Add one mana of any color. Activate only once each turn.

Sculpting Steel

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

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.

Jhoira, Weatherlight Captain

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

Command Tower

Drossforge Bridge

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

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.

Gold Myr

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.

Wake the Past

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

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.

Parcel Myr

Exotic Orchard

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

Hovermyr

Etherium Sculptor

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

Silverbluff Bridge

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

Steel Overseer

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

Palladium Myr

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.

Thoughtcast

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

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.

Myr Sire

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

Alpha Myr

Alloy Myr

Darkmoss Bridge

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

Swamp

Myr Superion

Spend only mana produced by creatures to cast this spell.

Silver Myr

Tree of Tales

Myr Scrapling

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

Leaden Myr

Thornglint Bridge

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

Sarcomite Myr

{2}: Sarcomite Myr gains flying until end of turn.
{2}, Sacrifice Sarcomite Myr: Draw a card.

Shimmer Myr

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

Copper 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.

Myrsmith

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

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.

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 Kinsmith

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

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.)

Mistvault Bridge

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

Suntouched Myr

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

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.

Distant Melody

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

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.)