Diligent Excavator

Whenever you cast a historic spell, target player mills two cards. (Artifacts, legendaries, and Sagas are historic.)

Armguard Familiar

Ward {2} (Whenever this permanent becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Equipped creature gets +2/+1 and has ward {2}.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Network Disruptor

Flying
When Network Disruptor enters, tap target permanent.

Parcel Myr

Witching Well

When Witching Well enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Mnemonic Sphere

{1}{U}, Sacrifice Mnemonic Sphere: Draw two cards.
Channel — {U}, Discard Mnemonic Sphere: Draw a card.

Secret Door

Defender
{4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Moonsnare Prototype

{T}, Tap an untapped artifact or creature you control: Add {C}.
Channel — {4}{U}, Discard Moonsnare Prototype: The owner of target nonland permanent puts it on their choice of the top or bottom of their library.

Aether Spellbomb

{U}, Sacrifice Aether Spellbomb: Return target creature to its owner's hand.
{1}, Sacrifice Aether Spellbomb: Draw a card.

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.")

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Etherium Sculptor

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

Silver Raven

Flying
When Silver Raven enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Malcator's Watcher

Flying, vigilance
When Malcator's Watcher dies, draw a card.

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

The Blackstaff of Waterdeep

You may choose not to untap The Blackstaff of Waterdeep during your untap step.
Animate Walking Statue — {1}{U}, {T}: Another target nontoken artifact you control becomes a 4/4 artifact creature for as long as The Blackstaff of Waterdeep remains tapped. Activate only as a sorcery.

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.)

Escaped Experiment

Whenever Escaped Experiment attacks, target creature an opponent controls gets -X/-0 until end of turn, where X is the number of artifacts you control.

Silver Myr

Corridor Monitor

When Corridor Monitor enters, untap target artifact or creature you control.

Vantress Gargoyle

Flying
Vantress Gargoyle can't attack unless defending player has seven or more cards in their graveyard.
Vantress Gargoyle can't block unless you have four or more cards in hand.
{T}: Each player mills a card.