Osgir, the Reconstructor

Most artifact recursion in Boros wants to reanimate one thing and hit it hard; this Giant instead treats the graveyard as a mold. The second ability does not return an artifact: it exiles one and stamps out two fresh copies, sorcery-speed only, at a cost scaling with the exiled card's mana value. That token-doubling changes the strategic axis entirely. Where a Goblin Welder or a Daretti loops the same artifact in and out, Osgir converts a single dead artifact into a pair of new permanents, which turns cheap trinkets into engines (two more mana rocks, two more pieces of equipment) and expensive bombs into a windfall you get to spend only once per copy. The exile cost enforces the arithmetic: each artifact in the yard is a one-time reagent rather than a recyclable one, so the deck wants a steady supply of things to feed rather than a single high-value target to protect. The first ability is the quieter half, a sacrifice outlet that pumps a creature by trading away an artifact you were probably going to exile for value anyway, giving the crematory theme a combat outlet. The 4/4 vigilance body is almost beside the point; the card's identity lives in the graveyard, in the math of turning one artifact into two.