Great Mazinger
In the modern "Mazinkaiser", Koji returns again to pilot Mazinger Z, alongside Tetsuya with his Great Mazinger. Mazinger Z was captured and was transformed by Dr. Hell to be an evil robot bent on destroying the world. Koji was redirected by his Hover Pilder to find Mazinkaiser and saves Great Mazinger, the Photonic institute, and eventually almost destroying Mazinger Z.