Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.

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

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

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.

Leaden Myr

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

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.

Dispatch

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

Foundry Inspector

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

Vault of Whispers

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Spire of Industry

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

Myr Enforcer

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

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Farseek

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

Glimmervoid

At the beginning of the end step, if you control no artifacts, sacrifice Glimmervoid.
{T}: Add one mana of any color.

Ferocity of the Wilds

Attacking non-Human creatures you control get +1/+0 and have trample.

Arcane Signet

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

Darkmoss Bridge

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Tempered Steel

Artifact creatures you control get +2/+2.

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.

Thornglint Bridge

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

Alloy Myr

Rustvale Bridge

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

Great Furnace

Sol Ring

Unwinding Clock

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

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

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.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Explore

You may play an additional land this turn.
Draw a card.

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Drossforge Bridge

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

Unravel the Aether

Choose target artifact or enchantment. Its owner shuffles it into their library.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Statue

Destroy target artifact, creature, or enchantment.

Status

Target creature gets +1/+1 and gains deathtouch until end of turn.

Status // Statue

Despark

Exile target permanent with mana value 4 or greater.

Mountain

Swamp

Myr Retriever

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

Mistvault Bridge

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

Tanglepool Bridge

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

Command Tower

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

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.)

Thopter Spy Network

At the beginning of your upkeep, if you control an artifact, create a 1/1 colorless Thopter artifact creature token with flying.
Whenever one or more artifact creatures you control deal combat damage to a player, draw a card.

Ancient Den

Goldmire Bridge

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

Shimmer Myr

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

Notion Rain

Surveil 2, then draw two cards. Notion Rain deals 2 damage to you. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Doom Blade

Myr Sire

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

Origin Spellbomb

{1}, {T}, Sacrifice Origin Spellbomb: Create a 1/1 colorless Myr artifact creature token.
When Origin Spellbomb is put into a graveyard from the battlefield, you may pay {W}. If you do, draw a card.

Forest

Silverbluff Bridge

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

Silver Myr

Secrets of the Golden City

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Draw two cards. If you have the city's blessing, draw three cards instead.

Thoughtcast

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

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.

Razortide Bridge

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

Go for the Throat

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Hovermyr

Perilous Myr

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

Plains

Fellwar Stone

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

Slagwoods Bridge

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

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Shrine of Loyal Legions

At the beginning of your upkeep and whenever you cast a white spell, put a charge counter on Shrine of Loyal Legions.
{3}, {T}, Sacrifice Shrine of Loyal Legions: Create a 1/1 colorless Phyrexian Myr artifact creature token for each charge counter on Shrine of Loyal Legions.

Darksteel Citadel

Island

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.

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Iron Myr

Copper Myr

Myrsmith

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

Exotic Orchard

Myr Galvanizer

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

Palladium Myr

Steel Overseer

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

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

Gold Myr

Garth One-Eye

{T}: Choose a card name that hasn't been chosen from among Disenchant, Braingeyser, Terror, Shivan Dragon, Regrowth, and Black Lotus. Create a copy of the card with the chosen name. You may cast the copy. (You still pay its costs.)