Etched Champion

Metalcraft — This creature has protection from each color as long as you control three or more artifacts.

Memnite

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Snow-Covered Island

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach this Equipment to target creature you control.
Equip {1}

Ornithopter

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}

Jegantha, the Wellspring

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Tear

Destroy target enchantment.
Fuse (You may cast one or both halves of this card from your hand.)

Wear

Destroy target artifact.
Fuse (You may cast one or both halves of this card from your hand.)

Wear // Tear

Welding Jar

Sacrifice this artifact: Regenerate target artifact.

Mishra's Bauble

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

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

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}

Thought Monitor

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

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

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.

Frogmite

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Darksteel Citadel

Silverbluff Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {R}.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Signal Pest

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
This creature can't be blocked except by creatures with flying or reach.

Spire of Industry

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

Pithing Needle

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