Myr Enforcer

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

Wargate

Search your library for a permanent card with mana value X or less, put it onto the battlefield, then shuffle.

Myr Servitor

At the beginning of your upkeep, if this creature is on the battlefield, each player returns all cards named Myr Servitor from their graveyard to the battlefield.

Urza's Filter

Multicolored spells cost {2} less to cast.

Karn, Scion of Urza

+1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it.
−1: Put a card you own with a silver counter on it from exile into your hand.
−2: Create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

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 this creature becomes blocked, it gets +2/+2 until end of turn.

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, this artifact deals 10 damage to each opponent.

Myr Sire

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

Urza's Bauble

{T}, Sacrifice this artifact: Look at a card at random in target player's hand. You draw a card at the beginning of the next turn's upkeep.

Leaden Myr

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Urza, Chief Artificer

Affinity for artifact creatures (This spell costs {1} less to cast for each artifact creature you control.)
Artifact creatures you control have menace.
At the beginning of your end step, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Palladium Myr

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Perilous Myr

When this creature dies, it deals 2 damage to any target.

Urza, Powerstone Prodigy

Vigilance
{1}, {T}: Draw a card, then discard a card.
Whenever you discard one or more artifact cards, create a tapped Powerstone token. This ability triggers only once each turn. (The token is an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Urza's Cave

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

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.)

Myr Propagator

{3}, {T}: Create a token that's a copy of this creature.

Myr Kinsmith

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

Hovermyr

Myr Moonvessel

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Parcel Myr

{2}, Sacrifice this creature: Draw a card.

Myr Landshaper

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

Glasses of Urza

Urza's Workshop

{T}: Add {C}.
Metalcraft — {T}: Add {C} for each Urza's land you control. Activate only if you control three or more artifacts.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Suntouched Myr

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

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.

Iron Myr

Silver Myr

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.

Myr Mindservant

Myr Quadropod

{3}: Switch this creature's power and toughness until end of turn.

Urza's Blueprints

Echo {6} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
{T}: Draw a card.

Urza, Lord Protector

Artifact, instant, and sorcery spells you cast cost {1} less to cast.
{7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Urza's Chalice

Whenever a player casts an artifact spell, you may pay {1}. If you do, you gain 1 life.

Myr Superion

Spend only mana produced by creatures to cast this spell.

Shimmer Myr

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

Urza, Lord High Artificer

When Urza enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Myr Welder

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

Urza, Academy Headmaster

+1: Head to AskUrza.com and click +1.
−1: Head to AskUrza.com and click -1.
−6: Head to AskUrza.com and click -6.

Gold Myr

Alloy 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.

Myr Prototype

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

Myr Adapter

This creature gets +1/+1 for each Equipment attached to it.

Copper Myr

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}.

Myr Battlesphere

When this creature enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever this creature attacks, you may tap X untapped Myr you control. If you do, this creature gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Liberator, Urza's Battlethopter

Flash
Flying
You may cast colorless spells and artifact spells as though they had flash.
Whenever you cast a spell, if the amount of mana spent to cast that spell is greater than Liberator's power, put a +1/+1 counter on Liberator.

Myr Custodian

When this creature 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.)

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 Galvanizer

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