Iron Man, Bleeding Edge

Doubling a spell is one of the loudest effects in blue's toolbox, and the usual price for it is a whole card and a chunk of mana: Fork, Twincast, the various copy-a-spell instants that ask you to hold up mana and hope the target is worth it. Here the copy comes for free off a trigger that fires whenever you cast an artifact spell, so the deck no longer has to spend a slot on the doubler; it just has to keep the body alive and keep casting artifacts it already wanted to cast. The once-per-turn clamp is what keeps the engine from tipping into oppression: one copy, not a chain, so the reward goes to whoever casts their single highest-impact artifact rather than to whoever storms out a hand of trinkets. Stripping legendary from the copy is the giveaway that this was built with commanders and marquee artifacts in mind, letting you duplicate a piece the legend rule would otherwise forbid you from fielding twice. Structurally it belongs to a lineage of build-around blue value pieces that turn one axis of a deck into two, but where a general spell-copier hedges across all instants and sorceries, this commits fully to the artifact axis and makes that commitment its whole identity. The 3/5 flying body earns its keep too: it blocks, it clocks, and it survives the cheap removal that would otherwise blank a five-mana engine before it triggers once.