Mirrodin Besieged

As Mirrodin Besieged enters, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

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.

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.

Sarcomite Myr

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

Lodestone Myr

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

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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.

Myr Retriever

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

Myr Galvanizer

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

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.

Shimmer Myr

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

Parcel Myr

Arcane Signet

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

Suntouched Myr

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

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.

Silver Myr

Gold Myr

Alloy Myr

Myrsmith

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

Master's Call

Create two 1/1 colorless Myr artifact creature tokens.

Island

Hovermyr

Plains

Myr Scrapling

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

Mistveil Plains

({T}: Add {W}.)
Mistveil Plains enters tapped.
{W}, {T}: Put target card from your graveyard on the bottom of your library. Activate only if you control two or more white permanents.

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.

Sol Ring

Worn Powerstone

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

Forest

Mountain

Myr Sire

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

Myr Moonvessel

Myr Landshaper

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

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.

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.

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.

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.)

Commander's Sphere

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

Leaden Myr

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Myr Kinsmith

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

Perilous Myr

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

Myr Enforcer

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

Swamp

Iron Myr

Majestic Myriarch

Majestic Myriarch's power and toughness are each equal to twice the number of creatures you control.
At the beginning of each combat, Majestic Myriarch gains flying until end of turn if you control a creature with flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Palladium Myr

Myr Propagator

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

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.

Thran Dynamo

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.

Copper Myr

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.

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.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Myr Welder

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