Boomerang Max (MA-9) is one of the Proto-Max Units. He is seen attacking Bomber Zero, but when the Jetters retreated he had to face Bomber Chen, Pretty Bomber, and four other Bombermen. He was later seen keeping Jetters from stopping the arms. He is defeated by Bomber Zero after a failed attack method. He is later summoned by MechaDoc to form the Dark Force Bomber. After Dark Force Bomber's downfall, Boomerang Max is destroyed for good.