Kagami Praeside is a childhood friend of Ryou's (now Arbiter), as well as his lover. She died in the midst of a fight between Ryou and Malovus within the last hours of the war that destroyed their homeworld Terralius.
Kagami, at the age of six, found a four-year-old Ryou abandoned in the streets. Taking him under her wing, Kagami brought him to her "family", consisting of a group of other orphans- Jason, Malovus, and Amber.
Ryou happily grew up in this family, despite abuse from Malovus. He and Kagami eventually became lovers, and before Ryou's adulthood, they bore a child whom they named after Jason, who died a few years earlier.
Malovus at the time rose to power, becoming the new Fuhrer, and secretly incited the Science-Magic War. He kidnapped Ryou to break down his mind and turn him into a bioweapon using Thaumaturgy. Kagami, carrying a young Jason to protect him from the war breaking out in the city below, found Ryou and interrupted Malovus' experiment. A fight broke out, and at the end, Malovus had disappeared, while Kagami and young Jason lay dead.
Years later, Malovus, having survived the battle, uploaded his mind and soul into a computer using advanced Thaumaturgy. He cloned Jason back to life, who eventually became Thirteen. Kagami, on the other hand, was brought back to life and transferred to the world of Aegis, where she was found and taken into Phoenix Industries to be used as a test subject...