Perserk Von Fallen

In the ancient times, Perserk was the Demon King. She was raised by the sword god Ares. As the was between demons and humans escalated, Ares had to defeat Perserk and seal her inside the Divine Sword Caldeiras. She is accidentally released from there by Davy and attached to his stigmata instead. She mostly shows herself to Davy as an 8 inch shoulder fairy, but it seems she can temporarily adopt the size of a normal adult at times.