Madnug was a member of the Super Dimensional Guard, but vanished after an experiment in space warp technology failed. Rescued by General Zeong he takes on a new identity in service to his new master, becoming Professor Gerbera to mask his true identity.

Madmug, now the Dark Axis' chief science officer, Second-in-Command, and Sazabi's immediate superior, Gerbera is fiercely loyal to the goals of the Dark Axis. Despite resembling any other Dark Axis robot, this is just a disguise for Gebera's true form- Madnug, a Neotopian Gundam and 'brother' unit of Captain flung from the future by a terrible accident. Brainwashed into believing humans are evil creatures, he attempts to sway Captain to their cause and when this proves impossible attempts to kill him. In their final battle he is badly damaged and as a final act of defiance prepares to sacrifice himself for the rebirth of Zeong. Captain attempts to stop him, offering to return him to Neotopia. Madnug however cannot escape his brainwashing and jumps into a melting pit, ending his tormented life. Madnug wielded a pair of beam rifles, usually stored inside of two of his three thruster pods. The two separate weapons could combine into a singular beam rifle.