Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Aragorn, Hornburg Hero

Attacking creatures you control have first strike and renown 1. (When a creature with renown 1 deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a renowned creature you control deals combat damage to a player, double the number of +1/+1 counters on it.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

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.

Research Thief

Flash
Flying
Whenever an artifact creature you control deals combat damage to a player, draw a card.

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Myr Galvanizer

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

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is Kami of Whispered Hopes's power.

Arcane Adaptation

As Arcane Adaptation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Tanglepool Bridge

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

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Myr Moonvessel

Goldmire Bridge

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

Razortide Bridge

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

Command Tower

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

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Kindred Discovery

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

Urza's Incubator

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

Adaptive Automaton

As Adaptive Automaton enters, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Jhoira, Weatherlight Captain

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

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, Lux Artillery deals 10 damage to each opponent.

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.

Retaliator Griffin

Flying
Whenever a source an opponent controls deals damage to you, you may put that many +1/+1 counters on Retaliator Griffin.

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

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.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

Great Furnace

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.

Spire of Industry

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

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

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.

Alloy Myr

Arcane Signet

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Arcum Dagsson

{T}: Target artifact creature's controller sacrifices it. That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle.

Shalai and Hallar

Flying, vigilance
Whenever one or more +1/+1 counters are put on a creature you control, Shalai and Hallar deals that much damage to target opponent.

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Steel Overseer

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

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.

Don't Have

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.

Copper Myr

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Foundry Inspector

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

Song of Freyalise

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Until your next turn, creatures you control gain "{T}: Add one mana of any color."
III — Put a +1/+1 counter on each creature you control. Those creatures gain vigilance, trample, and indestructible until end of turn.

Radiant Destiny

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
As Radiant Destiny enters, choose a creature type.
Creatures you control of the chosen type get +1/+1. As long as you have the city's blessing, they also have vigilance.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Ripples of Potential

Proliferate, then choose any number of permanents you control that had a counter put on them this way. Those permanents phase out. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

The First Tyrannic War

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You may put a creature card from your hand onto the battlefield. If its mana cost contains {X}, it enters with a number of +1/+1 counters on it equal to the number of lands you control.
II, III — Double the number of each kind of counter on target creature you control.

Changeling Outcast

Changeling (This card is every creature type.)
Changeling Outcast can't block and can't be blocked.

Chromatic Lantern

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

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.

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.

Master Biomancer

Each other creature you control enters with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Sword of Hours

Whenever equipped creature attacks, put a +1/+1 counter on it.
Whenever equipped creature deals combat damage, roll a d12. If the result is greater than the damage dealt or the result is 12, double the number of +1/+1 counters on that creature.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Rustvale Bridge

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

Eternity Vessel

Eternity Vessel enters with X charge counters on it, where X is your life total.
Landfall — Whenever a land you control enters, you may have your life total become the number of charge counters on Eternity Vessel.

Deepglow Skate

When Deepglow Skate enters, double the number of each kind of counter on any number of target permanents.

Mistvault Bridge

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

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.

Brokers Ascendancy

At the beginning of your end step, put a +1/+1 counter on each creature you control and a loyalty counter on each planeswalker you control.

Mountain

Myr Mindservant

Drossforge Bridge

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

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.)

Ardenvale Fealty

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the enchantment later from exile.)

Virtue of Loyalty

At the beginning of your end step, put a +1/+1 counter on each creature you control. Untap those creatures.

Virtue of Loyalty // Ardenvale Fealty

Court of Garenbrig

When Court of Garenbrig enters, you become the monarch.
At the beginning of your upkeep, distribute two +1/+1 counters among up to two target creatures. Then if you're the monarch, double the number of +1/+1 counters on each creature you control.

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.

Ozolith, the Shattered Spire

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead.
{1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.
Cycling {2} ({2}, Discard this card: Draw a card.)

Exotic Orchard

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

Island

Amoeboid Changeling

Changeling (This card is every creature type.)
{T}: Target creature gains all creature types until end of turn.
{T}: Target creature loses all creature types until end of turn.

Thornglint Bridge

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

Omarthis, Ghostfire Initiate

Omarthis, Ghostfire Initiate enters with X +1/+1 counters on it.
Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.
When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.

Myr Kinsmith

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

Cryptolith Rite

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

The Millennium Calendar

Whenever you untap one or more permanents during your untap step, put that many time counters on The Millennium Calendar.
{2}, {T}: Double the number of time counters on The Millennium Calendar.
When there are 1,000 or more time counters on The Millennium Calendar, sacrifice it and each opponent loses 1,000 life.

Forest

Fractal Harness

When Fractal Harness enters, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach Fractal Harness to it.
Whenever equipped creature attacks, double the number of +1/+1 counters on it.
Equip {2}

Vault of Whispers

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Ancient Den

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature 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.

Door of Destinies

As Door of Destinies enters, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Sol Ring

All Will Be One

Whenever you put one or more counters on a permanent or player, All Will Be One deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Elven Chorus

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
Creatures you control have "{T}: Add one mana of any color."

Crystalline Crawler

Converge — Crystalline Crawler enters with a +1/+1 counter on it for each color of mana spent to cast it.
Remove a +1/+1 counter from Crystalline Crawler: Add one mana of any color.
{T}: Put a +1/+1 counter on Crystalline Crawler.

Sage of Hours

Heroic — Whenever you cast a spell that targets Sage of Hours, put a +1/+1 counter on it.
Remove all +1/+1 counters from Sage of Hours: For each five counters removed this way, take an extra turn after this one.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Crystal Quarry

{T}: Add {C}.
{5}, {T}: Add {W}{U}{B}{R}{G}.

Unwinding Clock

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

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Symmetry Matrix

Whenever a creature you control with power equal to its toughness enters, you may pay {1}. If you do, draw a card.

Darkmoss Bridge

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

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}.

Palladium Myr

Slagwoods Bridge

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

Seat of the Synod

Myr Welder

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