So is he a demon that became a barber, or is he a barber who became a demon?
Yes...;-)
Actually he’s sent off to prison on a false charge because the judge wants his wife and he returns to seek revenge.
No, if he was a demon that became a barber, then he would be called a Barber Demon. He must be a barber who decided to become a demon. Of course, he could just be a barber that cuts hair for demons.