Précieuse is a divine weapon given to Jeanne d'Arc by the gods.
The archangel Michael gave the Précieuse to Jeanne as a reward for her services. Jeanne was to use this sword to cut down demons and the enemies of the gods. However, Charioce XIII became envious that Jeanne was the one to receive such a blessing and not him. In retaliation, Charioce XIII ordered her execution.
As Jeanne was being burned at the stake, Martinet convinced her that the gods had abandoned her. He offered Jeanne a chance to get her revenge and Jeanne agreed. The demon transformed Jeanne into another demon, allowing her to escape her execution and travel to the battlefield.