Bazillian wrote the song Ugly originally for someone else. But this doesn't mean that Jon didn't take any changes. As long as he worked a little bit on the song, he is credited as the songwriter. That Jon is mentioned as the writer doesn't let you see how much he wrote of the song. As long as he wrote a part of it or brought in his ideas, he is one of the songwriters. Remember, Desmond Child got songwriting credits for Prayer even though he only had the idea with the talkbox.