Full Moon Requiem
Ever the daredevil, Calista awoke in hospital one day after a motorbike race within Paragon went terribly wrong. Unable to feel her legs she thought her days of thrill and excitement were over when an opportunity showed itself. The former Nictus Void Sun approached her, seeking desperately for a host, with the promise: "I'll show you things far more exciting than what you ever knew!"
Born to a working class family, Calista always tried her best to make a name for herself, even in school. This led to her becoming kind of a bully in time as she used her physical prowess, despite her rather limited size, to get the attention she wanted. She would never back down from a fight and while her methods of winning the brawls she got into were often questionable, her reputation as someone not to be messed with quickly spread throughout every school she attended. In high school Calista started to work several side jobs in order to save up for her dream, her own motor bike. Her grades suffered greatly from her constantly sleeping in class so she could work late jobs, often staying up all night and eventually she would drop out of school completely. Instead, she attended motorbike races, both official and unofficial ones, with the first cheap bike she bought. Especially in unsavory circles her talent was quickly recognized, her relentless approach to driving and her general daredevil attitude. Calista started to parttake in more and more illegal races throughout Paragon's streets, quickly becoming well recognized as the "Red Devil".
The money from the races was enough to make a good living and Calista never questioned her way of living until the PPD decided to crack down hard on the illegal racing scene. One night, during a race sponsored by The Family, Calista and her competitors found themselves followed by several police cars, chased over the Skyway right into a blockade. When she awoke days later in the Skyway City hospital Calista couldn't quite remember what had happened, but police reports state that she dove off of the skyway in an extremely reckless stunt and finally crashed into a small café at a street corner, completely wrecking the place. Thankfully, she survived the crash, if only barely. Calista wasn't able to feel most of her limbs, her right arm as well as her legs, when she regained consciousness and she was told to never be able to fully use them again. It was likely she was stuck to a wheelchair for the rest of her life while facing severe debts and punishment with the damage she caused.
The universe is a dark and scary place. Shivans, multidimensional entities and even worse can be found everywhere if you just look long enough. Void Sun never quite answers the question about their own transformation but they clearly show regret about taking this dark path for such a long time. "It was necessary at the time.", might be the only explanation they ever gave. When Void Sun arrived on earth, together with their brethren, they became deeply involved in plans to take over the planet, taking several hosts at multiple times in history when they weren't sleeping away the years as a nictus cyst until they were awoken again. It might have been the crimes commited at their time with the Council that reminded the nictus of why they originally chose this path. "I had become what I had sworn to fight. Just another horror in this universe." When former collegues started facing off against the Council, calling themselves warshades, Void Sun was sceptical at first but in time their resolve grew: "There was no way I could continue like I acted before. It was time to remember what was important to me, millenia ago."
Full Moon Requiem
Upon merging, the newly formed warshade worked hard on regaining control over her body. Shifting between forms again and again they eventually managed to fix the severed nerves in Calista's spine. The FBSA of course took quick notice of the new warshade and SERAPH reached out to Requiem within days. The offer was clear: Instead of years in the Zig and enormous debts Requiem would use their talents to work for the FBSA, effectively working off her debts as a professional hero. The warshade was sceptical at first but decided to accept Shadowstar's conditions and soon after being released from hospital they already started out infiltrating Council bases and taking on special missions for SERAPH. Void Sun's promise quickly became true in more ways than even the reformed Kheldian had expected. Hero work quickly replaced the constant search for a new adrenaline kick and both sides felt right at home in their new occupation, as the daredevils they were as much as for idological reasons.