Isuka Suginami

Ikaruga's "twin" sister who was previously affiliated with the Alchemists before allying herself with Valhalla after promising them to revive the mythical dark elves.

Isuka in her early days was extremely content with researching and developing with Ikaruga and showed enthusiasm and youthful exuberance. She also exhibits stubbornness in going against their purpose to continuously innovate and became spiteful when Ikaruga left her. After many years alone, Isuka became further embittered about being abandoned (but slightly regretful in not following) and her punishment from her superiors had her emotions and thoughts suppressed. Fittingly, she still knows very little about how the outside world works and her lack of "humanity" surprised Haunted.

(Source: Taimadou Gakuen 35 Wiki)