Mirrodin Besieged

As Mirrodin Besieged enters the battlefield, 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 Galvanizer

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

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Time Sieve

{T}, Sacrifice five artifacts: Take an extra turn after this one.

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.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Plains

Sea of Clouds

Sea of Clouds enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

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.

Farseek

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

Island

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Mana Echoes

Whenever a creature enters the battlefield, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Perilous Myr

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

Cover of Darkness

As Cover of Darkness enters the battlefield, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Myrsmith

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

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Undergrowth Stadium

Undergrowth Stadium enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Myr Sire

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

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Copper Myr

Secluded Courtyard

As Secluded Courtyard enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Moonshaker Cavalry

Flying
When Moonshaker Cavalry enters the battlefield, creatures you control gain flying and get +X/+X until end of turn, where X is the number of creatures you control.

Morphic Pool

Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

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.

Command Tower

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

Mount Doom

{T}, Pay 1 life: Add {B} or {R}.
{1}{B}{R}, {T}: Mount Doom deals 1 damage to each opponent.
{5}{B}{R}, {T}, Sacrifice Mount Doom and a legendary artifact: Choose up to two creatures, then destroy the rest. Activate only as a sorcery.

Concordant Crossroads

Hovermyr

Black Market Connections

At the beginning of your precombat main phase, choose one or more —
• Sell Contraband — Create a Treasure token. You lose 1 life.
• Buy Information — Draw a card. You lose 2 life.
• Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

And They Shall Know No Fear

Choose a creature type. Creatures you control of the chosen type get +1/+0 and gain indestructible until end of turn.

Spire of Industry

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

Tezzeret, Master of the Bridge

Creature and planeswalker spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)
+2: Tezzeret, Master of the Bridge deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
−3: Return target artifact card from your graveyard to your hand.
−8: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.

Myr Superion

Spend only mana produced by creatures to cast this spell.

Myr Propagator

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

Iron 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.

Folk Hero

Commander creatures you own have "Whenever you cast a spell that shares a creature type with this creature, draw a card. This ability triggers only once each turn."

Luxury Suite

Luxury Suite enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Jhoira, Weatherlight Captain

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

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}.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Arcane Signet

Triumph of the Hordes

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Exotic Orchard

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

Kindred Discovery

As Kindred Discovery enters the battlefield, choose a creature type.
Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

Glare of Subdual

Tap an untapped creature you control: Tap target artifact or creature.

Myr Kinsmith

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

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.

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Gold Myr

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from all colors until end of turn.

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.

Sol Ring

Bountiful Promenade

Bountiful Promenade enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Silver Myr

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.

Lodestone Myr

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

Myr Welder

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

Leaden Myr

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.)

Mountain

Urza's Incubator

As Urza's Incubator enters the battlefield, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Steely Resolve

As Steely Resolve enters the battlefield, choose a creature type.
Creatures of the chosen type have shroud. (They can't be the targets of spells or abilities.)

Steel Overseer

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

Vault of Champions

Vault of Champions enters the battlefield tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Rejuvenating Springs

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

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.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Training Center

Training Center enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Metalworker

{T}: Reveal any number of artifact cards in your hand. Add {C}{C} for each card revealed this way.

Alloy Myr

Forsaken Monument

Colorless creatures you control get +2/+2.
Whenever you tap a permanent for {C}, add an additional {C}.
Whenever you cast a colorless spell, you gain 2 life.

Swamp

Shimmer Myr

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

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Spire Garden

Spire Garden enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

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.

Rhystic Study

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

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Forest

Myr Retriever

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

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Spectator Seating

Spectator Seating enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.