Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Spire of Industry

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only if you control an artifact.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Glass Casket

When Glass Casket enters, exile target creature an opponent controls with mana value 3 or less until Glass Casket leaves the battlefield.

Ingenious Smith

When Ingenious Smith enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever one or more artifacts you control enter, put a +1/+1 counter on Ingenious Smith. This ability triggers only once each turn.

Portable Hole

When Portable Hole enters, exile target nonland permanent an opponent controls with mana value 2 or less until Portable Hole leaves the battlefield.

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Tezzeret, Betrayer of Flesh

The first activated ability of an artifact you activate each turn costs {2} less to activate.
+1: Draw two cards. Then discard two cards unless you discard an artifact card.
−2: Target artifact becomes an artifact creature. If it isn't a Vehicle, it has base power and toughness 4/4.
−6: You get an emblem with "Whenever an artifact you control becomes tapped, draw a card."

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

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.

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.

Island

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.

Plains

Esper Sentinel

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

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

Negate

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.

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}.