I've been trying to figure this one out. I the Workshop you can upgrade your arm and upgrade your sword. There is a travel tube. But it brings up a screen with 4 slots. Slot 1 on the left has Hob in it, the other three slots are empty.

Anyone have any idea what this is?

I'm on my 5th play through,and i think I just about found everything.... Just one more Butterfly...

Sad that Runic went out of business. Really love this game.

It's a wardrobe, essentially.
As you discover the schematics for the other outfits, and then purchase them, they become available in that tube.

And ditto; I really loved this game and respected the hell out of the team at the studio, such an awful thing for them to deal with, getting this out and then doors closed on them barely a month later.