Dude its performance magic, magic is mostly a mind game and people who are dumb enough to trust thier eyes only deserve to get fooled. lol.
I belive in chi too but it sure isn't what you see in naruto (chakra) and bleach (bankai) . I dont think it can extend that far from the body- if it does that person is dabbling in some serious evil stuff. The question is misleadin too you said supernatural, i think most chi is completely natural, just most people cant use it unless well trained. Just like any other skill, anime and movies just overdo it. lol.