OHHHHHHHH
WHAT???? HE KILLED HIS PARENTS????
JK. He didn't he just feels guilty about it.
This is the one part I am concerned about because this is his fatal flaw. If you read it carefully you can figure out what it is, but I didn't make it super direct which may be a problem.
His fatal flaw is that he thinks that he's evil, therefore he does evil things because the chosen one is supposed to be a hero, but he doesn't feel like a hero. He thinks he's a criminal, so he behaves like a criminal.