Ornithopter

Seat of the Synod

Reverse Engineer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Draw three cards.

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.)

Island

Quicksilver Behemoth

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Quicksilver Behemoth attacks or blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Broodstar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
Broodstar's power and toughness are each equal to the number of artifacts you control.

Memnite

Thoughtcast

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

Chromescale Drake

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Chromescale Drake enters, reveal the top three cards of your library. Put all artifact cards revealed this way into your hand and the rest into your graveyard.

Spellbook

Qumulox

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

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.

Frogmite

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

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Darksteel Citadel

Myr Enforcer

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}.