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.)

Depth Charge Colossus

Prototype {4}{U}{U} — 6/6 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Depth Charge Colossus doesn't untap during your untap step.
{3}: Untap Depth Charge Colossus.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Spire Golem

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

Foundry Inspector

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

Myr Enforcer

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

Thoughtcast

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

Mirrorshell Crab

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Channel — {2}{U}, Discard Mirrorshell Crab: Counter target spell or ability unless its controller pays {3}.

Battery Bearer

Creatures you control have "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell."
Whenever you cast an artifact spell with mana value 6 or greater, draw a card.

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Rust Goliath

Prototype {3}{G}{G} — 3/5 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Reach, trample

Thundersteel Colossus

Trample, haste
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Simic Signet

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Etherium Sculptor

Tangle Golem

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

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Etherium Spinner

Whenever you cast a spell with mana value 4 or greater, create a 1/1 colorless Thopter artifact creature token with flying.

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)