I love this idea cause it definitely removes alot of the mess you'd find either in artists galleries/design tabs aswell as easier for people to see that a character is co owned and not just that someone stole it???
There should be a co-owner box in the character page when you make a new one. A lot of people just make separate toyhouses for the co-owned characters and tag each other in it. But it'd be really nice if it just popped up in both peoples character list and when you uploaded art it would update both. It just feels like it could be a very nice feature for people instead of having to upload in fill out information separately.
+1 IF there was an implementation of each user having to confirm major changes (transferring the character, deleting the character, relinquishing all ownership, etc). otherwise this could easily be abused and misused. if two users have a falling out and they co-own a character, without those other implementations I just described one user could easily just delete the character or revoke ownership. basically TH would have to find a way to make sure each party consents to any major changes. (like when accepting character transfers, just make it pop up on both accounts to confirm major changes).