Mind Over Matter

Discard a card: You may tap or untap target artifact, creature, or land.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

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.

Thran Foundry

{1}, {T}, Exile this artifact: Target player shuffles their graveyard into their library.

Tower Worker

Reach
{T}: Add {C}. If you control creatures named Mine Worker and Power Plant Worker, add {C}{C}{C} instead.

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, 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."

Deadly Riposte

Deadly Riposte deals 3 damage to target tapped creature and you gain 2 life.

Thran Lens

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.

Power Plant Worker

{3}: This creature gets +2/+2 until end of turn. If you control creatures named Mine Worker and Tower Worker, put two +1/+1 counters on this creature instead. Activate only once each turn.

Dark Suspicions

At the beginning of each opponent's upkeep, that player loses X life, where X is the number of cards in that player's hand minus the number of cards in your hand.

Kayla's Music Box

{W}, {T}: Look at the top card of your library, then exile it face down. (You may look at it any time.)
{T}: Until end of turn, you may play cards you own exiled with Kayla's Music Box.

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.

Urza's Factory

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

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.

Sunglasses of Urza

You may spend white mana as though it were red mana.

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.

Rewards of Diversity

Whenever an opponent casts a multicolored spell, you gain 4 life.

Argivian Avenger

{1}: Until end of turn, this creature gets -1/-1 and gains your choice of flying, vigilance, deathtouch, or haste.

Urza's Command

Choose two —
• Creatures you don't control get -2/-0 until end of turn.
• Create a tapped Powerstone token.
• Create a tapped 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."
• Scry 1, then draw a card.

Urza's Rebuff

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

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's Avenger

{0}: This creature gets -1/-1 and gains your choice of banding, flying, first strike, or trample until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Mine Worker

{T}: You gain 1 life. If you control creatures named Power Plant Worker and Tower Worker, you gain 3 life instead.

Energy Refractor

When this artifact enters, draw a card.
{2}: Add one mana of any color.

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever this creature deals damage to an opponent, draw a card.

Urza's Armor

If a source would deal damage to you, prevent 1 of that damage.

Attunement

Return this enchantment to its owner's hand: Draw three cards, then discard four cards.

Glasses of Urza

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

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."

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.

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.

Thran Turbine

At the beginning of your upkeep, you may add {C}{C}. You can't spend this mana to cast spells.

Loran, Disciple of History

Whenever Loran or another legendary creature you control enters, return target artifact card from your graveyard to your hand.

Opposition

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

Urza's Tome

{3}, {T}: Draw a card. Then discard a card unless you exile a historic card from your graveyard. (Artifacts, legendaries, and Sagas are historic.)

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Urza's Guilt

Each player draws two cards, then discards three cards, then loses 4 life.

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.

Urza's Chalice

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

Mass Production

Create four 1/1 colorless Soldier artifact creature tokens.

Beast of Burden

Beast of Burden's power and toughness are each equal to the number of creatures on the battlefield.

Urza's Filter

Multicolored spells cost {2} less to cast.

Urza's Sylex

{2}{W}{W}, {T}, Exile Urza's Sylex: Each player chooses six lands they control. Destroy all other permanents. Activate only as a sorcery.
When Urza's Sylex is put into exile from the battlefield, you may pay {2}. If you do, search your library for a planeswalker card, reveal it, put it into your hand, then shuffle.

Urza's Engine

Trample
{3}: This creature gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)
{3}: Attacking creatures banded with this creature gain trample until end of turn.

Wall of Junk

Defender (This creature can't attack.)
When this creature blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Thran Dynamo

Confound

Counter target spell that targets a creature.
Draw a card.

Powerstone Shard

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

Rescue

Return target permanent you control to its owner's hand.

Word of Undoing

Return target creature and all white Auras you own attached to it to their owners' hands.

Machine Over Matter

This spell costs {1} less to cast if you control an artifact creature.
Return target nonland permanent to its owner's hand.

Angelic Curator

Mental Discipline

Urza's Power Plant

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

Pristine Talisman

Stroke of Genius

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.")

Absolute Grace

All creatures have protection from black.

Calamity's Wake

Exile all graveyards. Players can't cast noncreature spells this turn. Exile Calamity's Wake.

Sol Ring

Amulet of Kroog

{2}, {T}: Prevent the next 1 damage that would be dealt to any target this turn.