Counterspell

Oaken Siren

Flying, vigilance
{T}: Add {U}. Spend this mana only to cast an artifact spell or activate an ability of an artifact source.

Mirran Spy

Flying
Whenever you cast an artifact spell, you may untap target creature.

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

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.

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it 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.)

Sol Ring

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Foundry Inspector

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

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.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Niblis of the Breath

Flying
{U}, {T}: You may tap or untap target creature.

Lumengrid Sentinel

Flying
Whenever an artifact you control enters, you may tap target permanent.

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Lightning Greaves

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

Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Ornithopter

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.

Exhaustion

Creatures and lands target opponent controls don't untap during their next untap step.

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Ioreth of the Healing House

{T}: Untap another target permanent.
{T}: Untap two other target legendary creatures.

Fomori Vault

{T}: Add {C}.
{3}, {T}, Discard a card: Look at the top X cards of your library, where X is the number of artifacts you control. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Future Sight

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

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.

Forensic Gadgeteer

Whenever you cast an artifact spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Activated abilities of artifacts you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Thassa's Oracle

When Thassa's Oracle enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Spellbook

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Golem's Heart

Whenever a player casts an artifact spell, you may gain 1 life.

Manakin

Efficient Construction

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

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Academy Ruins

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

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Golem Foundry

Whenever you cast an artifact spell, you may put a charge counter on Golem Foundry.
Remove three charge counters from Golem Foundry: Create a 3/3 colorless Golem artifact creature token.

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Island

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.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

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.

Blinkmoth Urn

At the beginning of each player's first main phase, if Blinkmoth Urn is untapped, that player adds {C} for each artifact they control.

Aphetto Alchemist

{T}: Untap target artifact or creature.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Crystal Skull, Isu Spyglass

You may look at the top card of your library any time.
You may play historic lands and cast historic spells from the top of your library. (Artifacts, legendaries, and Sagas are historic.)
{T}: Add {U}.

Fortune Teller's Talent

(Gain the next level as a sorcery to add its ability.)
You may look at the top card of your library any time.
{3}{U}: Level 2
As long as you've cast a spell this turn, you may play cards from the top of your library.
{2}{U}: Level 3
Spells you cast from anywhere other than your hand cost {2} less to cast.

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Cyber Conversion

Turn target creature face down. It's a 2/2 Cyberman artifact creature.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Etherium Sculptor

Painter's Servant

As Painter's Servant enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Chimil, the Inner Sun

Spells you control can't be countered.
At the beginning of your end step, discover 5. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Aura of Dominion

Enchant creature
{1}, Tap an untapped creature you control: Untap enchanted creature.

In Too Deep

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Enchant creature, planeswalker, or Clue
Enchanted permanent is a colorless Clue artifact with "{2}, Sacrifice this artifact: Draw a card" and loses all other abilities. (It's no longer a creature or planeswalker.)