"Eden" once referred to a metaphorical human paradise on Zero, which could never be found. It's now a turn of phrase to refer to all the belongings of their children who went beyond. Paradise is the goal in their hearts, a place where the Universe and its brutal edicts can be torn apart. The books of law are held in the arsonist's hands.
Luna was by far the luckiest. They were always the closest to Zero; the most dependent. They learnt the hard way. In the years before the Days of Regret they knew best what they were like, what their rapacious siblings were capable of doing in the dark. They had prepared for the years to come, and had escaped the most of their wrath.
It would be their greatest challenge, at the price of near-everything. Dependent on Earth for supplies more than most,