I really pushed it further and changed the ship design.
Backstory: "Huge ships from mechanical nation called Transborders come regularly to collect
Backstory: "Due to severe mutilations after battles against the Mecha Nation, and less and less soldiers capable to fight, the Rebels developed weapons to adapt directly to the handicaped soldier who gets plugged-in to the mecha and thus would replace his missing legs in this case."
Back story: "Human rebels have started to overcome the Mecha nation and took back some of the infrastructures the mecha invaders built upon the former human society. Some troops are getting back there and are entering this gigantic turbine to join their underground headquarter."