Fafnir

An ancient hero who was held captive in Valhalla, the divine realm of infinite healing and infinite madness.

She was swallowed by Odin ages ago and used as an energy source for magic within his body.

Originally a skilled magician, and even after being held captive within Odin's body, she attempted to escape the labyrinth by sending a part of herself to the present world, using that as a connection to it. However, once her body was sent to the present world, it turned into a dragon and went berserk, and was defeated by Siegfried and disappeared. At that time, she lost part of her human intelligence.