Veil of Assimilation

Whenever Veil of Assimilation or another artifact you control enters, target creature you control gets +1/+1 and gains vigilance until end of turn.

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.

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.

Great Desert Prospector

When Great Desert Prospector enters, create a tapped Powerstone token for each other creature you control. (They're artifacts with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Against All Odds

Choose one or both —
• Exile target artifact or creature you control, then return it to the battlefield under its owner's control.
• Return target artifact or creature card with mana value 3 or less from your graveyard to the battlefield.

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 creature gets +1/+1 for each artifact you control."
• Scry 1, then draw a card.

Annex Sentry

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Annex Sentry enters, exile target artifact or creature an opponent controls with mana value 3 or less until Annex Sentry leaves the battlefield.

The Mycosynth Gardens

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

Circuit Mender

When Circuit Mender enters, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Plains

Malcator's Watcher

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

Island

Charge of the Mites

Choose one —
• Charge of the Mites deals damage equal to the number of creatures you control to target creature or planeswalker.
• Create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Platoon Dispenser

At the beginning of your end step, if you control two or more other creatures, draw a card.
{3}{W}: Create a 1/1 colorless Soldier artifact creature token.
Unearth {2}{W}{W}

Destroy Evil

Choose one —
• Destroy target creature with toughness 4 or greater.
• Destroy target enchantment.

Combat Thresher

Prototype {2}{W} — 1/1 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Double strike
When Combat Thresher enters, draw a card.

Swooping Lookout

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Malcator, Purity Overseer

When Malcator, Purity Overseer enters, create a 3/3 colorless Phyrexian Golem artifact creature token.
At the beginning of your end step, if three or more artifacts entered the battlefield under your control this turn, create a 3/3 colorless Phyrexian Golem artifact creature token.

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 the top or bottom of their library.

Cephalopod Sentry

Flying
Cephalopod Sentry's power is equal to the number of artifacts you control.

Soul Partition

Exile target nonland permanent. For as long as that card remains exiled, its owner may play it. A spell cast by an opponent this way costs {2} more to cast.

Plated Onslaught

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Creatures you control get +2/+1 until end of turn.