Julia was a kind woman who gave up her happiness for the sake of others. Her father remarked that she, like her ancestors, had inherited the trait of being mischievous, but she often sacrificed herself for other people. Many around her, such as Gisela and Cheri, have commented that Julia pushed herself over the limit when trying to help people on the battlefield, which eventually resulted in her death. Gisela was one who remained by Julia's side in during the latter's final moments.
Julia's soul was given to Yuri when she accepted the fate given to her by the Original King. She was betrothed to Adelbert, was Wolfram's teacher, and was incredibly skilled at medical maryoku. She appears to have the same views on humans and Mazoku as Yuri does, wanting both races to be at peace with each other, which signifies their similarities. She was very close to Conrad, and she gave him her pendant, which Conrad then gave to Yuri.
She met her future self, Yuri, just before the Lutenburg Division left for the battlefield. Her chance meeting with Yuri prodded her that she is making the right choice accepting her fate to be the soul of the next Demon King and that Yuri will heal the world in the future.
Her ancestor, Erhard Wincott, was one of the chosen that was entrusted with one of the Four Forbidden boxes, "The Mirror at the Bottom of the Sea". However, the younger brother, Christel Wincott, brought the box to Earth for safe keeping. Julia's blood is the key to the box, and Yuri inherited this trait of being a key from her.
When Yuri's body is taken over by the Original King, whose soul is taken over by Soushu, she saves Yuri by letting him remember that he has courage to fight and change the world.
