Myr Retriever

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

Workshop Assistant

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

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

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Whenever one or more artifacts you control enter, Ingenious Artillerist deals that much damage to each opponent.

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.