Luna grew up as an orphan in the kingdom of Dalkia. Her rough upbringing caused her to become hardened and ruthless. Eventually she became one of Dalkia's greatest soldiers and eventually became the commander of the Klessirpimdo, whom she thought of as her family.
You fight against her multiple times in the Chronicles of the Sword mode, the last time she fights you she wields Soul Calibur, but is still overcome. Later, she joins you in your battle against Strife Astlar, giving your character Soul Calibur.
Luna uses the Chinese Blade style, a fighting style that can be given to custom characters in Soul Calibur III.