I don't know if it's directly related, but perhaps also some of the motivation to do this came from the comic book/movie Watchmen. Essentially, except for one character in Watchmen (who can alter matter and reality itself in many ways), all the superheros from Watchmen are quite normal (i.e. no superpowers). Of course, some are mentally unstable, such as Rorschach, but they are all powerless people who decided to fight crime (not as much help the needy). As a matter of fact, Phantom Zero reminds me of Rorschach: went through a trauma in his life, keeps his identity anonymous, and most importantly, looks really creepy. You wouldn't want to run into either Rorschach or Phantom Zero in a dark alley