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.

Uthros Research Craft

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 12+.)
3+ | Whenever you cast an artifact spell, draw a card. Put a charge counter on this Spacecraft.
12+ | Flying
This Spacecraft gets +1/+0 for each artifact you control.

Gnome

Artificer Class

(Gain the next level as a sorcery to add its ability.)
The first artifact spell you cast each turn costs {1} less to cast.
{1}{U}: Level 2
When this Class becomes level 2, reveal cards from the top of your library until you reveal an artifact card. Put that card into your hand and the rest on the bottom of your library in a random order.
{5}{U}: Level 3
At the beginning of your end step, create a token that's a copy of target artifact you control.

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.

Krang, Utrom Warlord

Flying, trample, indestructible, haste
Other artifact creatures you control have flying, trample, indestructible, and haste.

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Clue

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.

Bronze Guardian

Double strike
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Other artifacts you control have ward {2}.
Bronze Guardian's power is equal to the number of artifacts you control.

Worldwalker Helm

If you would create one or more artifact tokens, instead create those tokens plus an additional Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")
{1}{U}, {T}: Create a token that's a copy of target artifact token you control.

Plains

Everflowing Chalice

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

Unctus, Grand Metatect

Other blue creatures you control have "Whenever this creature becomes tapped, draw a card, then discard a card."
Other artifact creatures you control get +1/+1.
{U/P}: Until end of turn, target creature you control becomes a blue artifact in addition to its other colors and types. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Uthros, Titanic Godcore

This land enters tapped.
{T}: Add {U}.
Station (Tap another creature you control: Put charge counters equal to its power on this Planet. Station only as a sorcery.)
12+ | {U}, {T}: Add {U} for each artifact you control.

Powerstone

{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control.
Other artifact creatures you control get +1/+1.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

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.

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."

Unwinding Clock

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

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.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever this creature or another artifact you control enters, put a +1/+1 counter on this creature. It can't be blocked this turn.

Cloud Key

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

Construct

This creature gets +1/+1 for each artifact you control.

Sculpting Steel

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

Urza, Planeswalker

You may activate the loyalty abilities of Urza twice each turn rather than only once.
+2: Artifact, instant, and sorcery spells you cast this turn cost {2} less to cast. You gain 2 life.
+1: Draw two cards, then discard a card.
0: Create two 1/1 colorless Soldier artifact creature tokens.
−3: Exile target nonland permanent.
−10: Artifacts and planeswalkers you control gain indestructible until end of turn. Destroy all nonland permanents.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Darksteel Citadel

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Counterspell

The Mycosynth Gardens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{X}, {T}: This land becomes a copy of target nontoken artifact you control with mana value X.

Palladium Myr

Illustrious Wanderglyph

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Other artifact creatures you control get +2/+2 as long as you have the city's blessing.
At the beginning of each upkeep, create a 1/1 colorless Gnome artifact creature token.

Hall of Tagsin

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

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.

Reliquary Tower

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

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

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 Assembles the Titans

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — Scry 4, then you may reveal the top card of your library. If a planeswalker card is revealed this way, put it into your hand.
II — You may put a planeswalker card with mana value 6 or less from your hand onto the battlefield.
III — You may activate the loyalty abilities of planeswalkers you control twice this turn rather than only once.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is this creature's power.

Meteor Golem

When this creature enters, destroy target nonland permanent an opponent controls.

{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard.)

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.

Sol Ring

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.")

The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Jhoira's Familiar

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

Gold Myr

Silver Myr

Oltec Matterweaver

Whenever you cast a creature spell, choose one —
• Create a 1/1 colorless Gnome artifact creature token.
• Create a token that's a copy of target artifact token you control.

Ornithopter of Paradise

Karn, Legacy Reforged

Karn's power and toughness are each equal to the greatest mana value among artifacts you control.
At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Steel Overseer

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

Cyberdrive Awakener

Flying
Other artifact creatures you control have flying.
When this creature enters, each noncreature artifact you control becomes a 4/4 artifact creature until end of turn.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Razortide Bridge

This land enters tapped.
Indestructible
{T}: Add {W} or {U}.

Arch of Orazca

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{T}: Add {C}.
{5}, {T}: Draw a card. Activate only if you have the city's blessing.

Emry, Lurker of the Loch

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

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 Mine

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

Food

{2}, {T}, Sacrifice this token: You gain 3 life.

Foundry Inspector

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

Thought Vessel

Island

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.

Cryptothrall

Protector — Other artifact creatures you control have hexproof.

Powerstone Shard

{T}: Add {C} for each artifact you control named Powerstone Shard.

Academy Ruins

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

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.

Lightning Greaves

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

Archway of Innovation

This land enters tapped unless you control an Island.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Simulacrum Synthesizer

When this artifact enters, scry 2.
Whenever another artifact you control with mana value 3 or greater enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Urza's Power Plant

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

Assembly-Worker

Thopter

Salvation Engine

Other artifact creatures you control get +2/+2.
Whenever this Vehicle attacks, return up to one target artifact card from your graveyard to the battlefield.
Crew 6

Azorius Signet

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the greatest mana value or tied for the greatest mana value, draw a card.

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Thran Dynamo

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.

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have this creature enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Tempered Steel

Artifact creatures you control get +2/+2.

Wurmcoil Engine

Deathtouch, lifelink
When this creature dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Urza's Factory

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Assembly-Worker artifact creature token.

Voyager Quickwelder

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 token: Add one mana of any color.")

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Losheel, Clockwork Scholar

Prevent all combat damage that would be dealt to attacking artifact creatures you control.
Whenever one or more artifact creatures you control enter, draw a card. This ability triggers only once each turn.