Astaroth (アスタロト Asutaroto?) is one of the main characters of the Ulysses: Jeanne d'Arc to Renkin no Kishi light novel and the main protagonists of the anime series. She is Montmorency's teacher and partner in alchemy.
She has a prideful personality, but having seven years mentally spent in Montmorency feels sense of self-reproach.
She was tortured by La Trémoille, She was aided by Montmorency and gave Montmorency knowledge of alchemy. After the battle at Agincourt, while fleeing with Montmorency, she met Jeanne in Don Lemi village.