Re-Engineer fodder producer, combo piece, epic commander, win con duplication.

Interesting, but not the right size for its cost. I know, you get something out of it, when it dies. Still the option to be useful while on the battlefield would be nice.

Maybe a 4/4? It's effect is deceptively big, and its body is still useable by exploit, so I don't thing it needs to be huge.

If you have one of these and another artifact, playing a duplicate of the legend actually gives you unlimited copies of the other artifact.

Unlimited copies? I don't see what you're saying.

What if it was "target artifact not named Gravortus"? That should prevent the infinite loop, but tracks funny.

Ah I think I see what you're saying now... hmmm. I guess the state based legend rule doesn't quite beat it out of the stack, eh?

Maybe "put a copy of target nonlegendary artifact" That would stop it and keep it elegant.

SBAs kill it before the trigger goes on the stack, but the trigger does go on the stack. Leads to a weird combo with Sharuum, Sculpting Steel, and something that cares about ETB or death triggers. I really like the nonlegendary restriction.

Nonlegendary is still not a hurdle if you play a Sculpting Steel first, without copying anything, and then play this to make lots of copies of the Sculpting Steel.

Note that this also effectively removes the "you control" restriction.

I think its ok for a 7 mana legend to combo out with one or two other artifacts, so long as the combo isn't just playing more of itself.