Chief of the Foundry

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

Myr Scrapling

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

Plate Armor

Equipped creature gets +3/+3 and has ward {1}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {3}. This ability costs {1} less to activate for each other Equipment 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.)

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.

Alibou, Ancient Witness

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

Mishra, Tamer of Mak Fawa

Permanents you control have "Ward—Sacrifice a permanent."
Each artifact card in your graveyard has unearth {1}{B}{R}. ({1}{B}{R}: Return the card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Foundry Assembler

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

Jegantha, the Wellspring

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Silver Myr

Spare Dagger

Equipped creature gets +1/+0 and has "Whenever this creature attacks, you may sacrifice Spare Dagger. When you do, this creature deals 1 damage to any target."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Perilous Myr

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

Instrument of the Bards

At the beginning of your upkeep, you may put a harmony counter on Instrument of the Bards.
{3}{G}, {T}: Search your library for a creature card with mana value equal to the number of harmony counters on Instrument of the Bards, reveal it, and put it into your hand. If that card is legendary, create a Treasure token. Then shuffle.

Brass Squire

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

Sarcomite Myr

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

Myr Mindservant

Leaden Myr

Myr Propagator

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

The Brothers' War

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create two tapped Powerstone tokens.
II — Choose two target players. Until your next turn, each creature they control attacks the other chosen player each combat if able.
III — The Brothers' War deals X damage to any target and X damage to any other target, where X is the number of artifacts you control.

Swamp

Myr Adapter

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

Plains

Myr Enforcer

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

Island

Parcel Myr

Stern Lesson

Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Shimmer Myr

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

Sibling Rivalry

Gain control of target artifact or creature until end of turn. Untap it. It gains haste until end of turn. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Vorpal Sword

Equipped creature gets +2/+0 and has deathtouch.
{5}{B}{B}{B}: Until end of turn, Vorpal Sword gains "Whenever equipped creature deals combat damage to a player, that player loses the game."
Equip {B}{B}

Hovermyr

Myr Landshaper

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

Gold Myr

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."

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 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.

Forest

Foundry Inspector

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

Lodestone Myr

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

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.

Stone Retrieval Unit

When Stone Retrieval Unit enters the battlefield, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Negate

Myr Superion

Spend only mana produced by creatures to cast this spell.

Slagstone Refinery

Whenever Slagstone Refinery or another nontoken artifact you control is put into a graveyard from the battlefield or is put into exile from the battlefield, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Arcane Signet

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

Command Tower

Greataxe

Equipped creature gets +4/+0.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)

Mindstatic

Counter target spell unless its controller pays {6}.

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.

Copper Myr

Foundry Champion

When Foundry Champion enters the battlefield, it deals damage to any target equal to the number of creatures you control.
{R}: Foundry Champion gets +1/+0 until end of turn.
{W}: Foundry Champion gets +0/+1 until end of turn.

Myr Sire

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

Hall of Tagsin

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Sol Ring

Bag of Tricks

{4}{G}, {T}: Roll a d8. Reveal cards from the top of your library until you reveal a creature card with mana value equal to the result. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Suntouched Myr

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

Myrsmith

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

Palladium Myr

Myr Moonvessel

Myr Galvanizer

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

Mountain

Thran Spider

Reach
When Thran Spider enters the battlefield, you and target opponent each create a tapped Powerstone token.
{7}: Look at the top four 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 a random order.

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.

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.

Master's Call

Create two 1/1 colorless Myr artifact creature tokens.

Powerstone Shard

{T}: Add {C} for each artifact you control named Powerstone Shard.

Gix's Caress

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Voltaic Key

Myr Quadropod

{3}: Switch Myr Quadropod's power and toughness until end of turn.

Fortifying Provisions

Creatures you control get +0/+1.
When Fortifying Provisions enters the battlefield, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

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.

Hero of the Dunes

When Hero of the Dunes enters the battlefield, return target artifact or creature card with mana value 3 or less from your graveyard to the battlefield.
Creatures you control with mana value 3 or less get +1/+0.

Alloy Myr

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.

Refurbish

Return target artifact card from your graveyard to the battlefield.

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

Shrine of Loyal Legions

At the beginning of your upkeep or 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.

Iron Myr

Puppet Strings

{2}, {T}: You may tap or untap target creature.

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.