Thread:Fandyllic/@comment-38936664-20191003013953/@comment-168424-20191003183628

If you create a derivative work it needs to be significantly different from the original to claim a separate copyright. There is no defined line, it usually has to get decided in the courts. Most derivative works are just copyright violations, but it is up to the copyright holder to enforce it, in most cases (except in the EU where they have put more of the burden on companies that distribute or host potentially copyright violating materials).

The best thing you can do is give credit to the original work. Trying to claim copyright on a derivative work is where it gets tricky. Just claiming it doesn't really mean anything.

I posted some examples of described scenarios by legal groups and an official EU FAQ in a forum thread, but I'm too lazy to dig it up right now.