Mazinger Z vs. Devilman is a 1973 animated movie that crossed over two then-popular Anime series, both of which were created by Manga artist Go Nagai. While fighting with some of his enemies Mazinger Z inadvertently knocks them into a volcano, where they crash into the prison of the Satan race and release Phoenix Jenny! Dr. Hell, learning of this, frees the rest of the Satan race and teams up... see more