Watch Power of Grayskull: The Definitive History of He-Man and the Masters of the Universe for Free: How to Stream the Movie Online at 123Movies. . This documentary looks to forge the greatest, most definitive, documentary on everything He-Man and the Masters of the Universe, She-Ra, the live action movie, New Adventures of He-Man, the 200x series and much more! They delve into the toys, comics, cartoons, and movies from all eras by talking to the artists, creators, executives and actors who helped make it a reality.