Unfinished tales is a very big No-No.
Even though, it would be a very fun game, "The failed stars from jump gather, and fight in the tournament, for a second chance at stardom!, meet the warriors that couldn't be, and help them reach their dreams of Friendship! Effort! Victory!"
Or something like the Captain Rainbow of Shonen Jump.
--- Update From New Post Merge ---
I really want Saitama and Kenshiro, the unlikely team.
Aparently there are issues between shueshia and Fist of the North Star authors. And One Punch Man is definitely Shueshia, but it's iin it's own webcomic world and asociated more with Young Jump.