[KRX]

Why not have Gosei Green as RoboKnight before he became RoboKnight? Why not have Megaforce Green be a warrior who fell in battle, but was then rebuilt as RoboKnight? Or, to play up the nostalgia factor, have Megaforce Green be an evil Ranger created by the Warstars to fight the Megaforce, but turns good and joins them. However, instead of losing his powers, he sacrifices himself to save the Megaforce, but is rebuilt as RoboKnight.

Just a thought.