Darksteel Citadel

Colossus of Akros

Defender, indestructible
{10}: Monstrosity 10. (If this creature isn't monstrous, put ten +1/+1 counters on it and it becomes monstrous.)
As long as Colossus of Akros is monstrous, it has trample and can attack as though it didn't have defender.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Rejuvenating Springs

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

Tree of Tales

Unwinding Clock

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

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Mycosynth Golem

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Artifact creature spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)

Noxious Gearhulk

Menace
When Noxious Gearhulk enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Akroma's Memorial

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

Thopter Spy Network

At the beginning of your upkeep, if you control an artifact, create a 1/1 colorless Thopter artifact creature token with flying.
Whenever one or more artifact creatures you control deal combat damage to a player, draw a card.

Forest

Platinum Emperion

Your life total can't change. (You can't gain or lose life. You can't pay any amount of life except 0.)

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Torrential Gearhulk

Flash
When Torrential Gearhulk enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Dimir Signet

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Island

Memnite

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Seat of the Synod

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

Simic Signet

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Ornithopter of Paradise

Phyrexian Triniform

When Phyrexian Triniform dies, create three 3/3 colorless Phyrexian Golem artifact creature tokens.
Encore {12} ({12}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Arcane Signet

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

Undergrowth Stadium

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

Kuldotha Forgemaster

{T}, Sacrifice three artifacts: Search your library for an artifact card, put it onto the battlefield, then shuffle.

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.

Copper Myr

Kamahl, Heart of Krosa

At the beginning of combat on your turn, creatures you control get +3/+3 and gain trample until end of turn.
{1}{G}: Until end of turn, target land you control becomes a 1/1 Elemental creature with vigilance, indestructible, and haste. It's still a land.
Partner (You can have two commanders if both have partner.)

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Foundry Inspector

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

Sai, Master Thopterist

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.
{1}{U}, Sacrifice two artifacts: Draw a card.

Vineglimmer Snarl

As Vineglimmer Snarl enters, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters tapped.
{T}: Add {G} or {U}.

Reverse Engineer

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

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.
As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Counterspell

Ornithopter

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Shimmer Myr

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

Sultai Charm

Choose one —
• Destroy target monocolored creature.
• Destroy target artifact or enchantment.
• Draw two cards, then discard a card.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

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.

Sol Ring

Verdurous Gearhulk

Trample
When Verdurous Gearhulk enters, distribute four +1/+1 counters among any number of target creatures you control.

Tanglepool Bridge

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

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.

Steel Overseer

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

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.

Stoic Rebuttal

Metalcraft — This spell costs {1} less to cast if you control three or more artifacts.
Counter target spell.

Golgari Signet

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

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.

Leaden Myr

Silas Renn, Seeker Adept

Deathtouch
Whenever Silas Renn, Seeker Adept deals combat damage to a player, choose target artifact card in your graveyard. You may cast that card this turn.
Partner (You can have two commanders if both have partner.)

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.

Mistvault Bridge

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

Swamp

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Silver Myr

Farseek

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

Darkmoss Bridge

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

Thoughtcast

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

Vault of Whispers

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Padeem, Consul of Innovation

Artifacts you control have hexproof.
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Morphic Pool

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

Command Tower

Time Sieve

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

Myr Enforcer

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

Necroblossom Snarl

As Necroblossom Snarl enters, you may reveal a Swamp or Forest card from your hand. If you don't, Necroblossom Snarl enters tapped.
{T}: Add {B} or {G}.

Choked Estuary

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Etherium Sculptor

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.