Workshop Assistant

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

Urza's Tower

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

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

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

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

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

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

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

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

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