Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Halo Hopper

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Barricade Breaker

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Barricade Breaker attacks each combat if able.

Scale of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +0/+1 until end of turn.

Will-Forged Golem

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

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.)

Ornithopter

Foundry Assembler

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

Memnite

Frogmite

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

Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Phyrexian Walker

Myr Enforcer

Tooth of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +1/+0 until end of turn.