Xianxia: Guardian of the Young Miss

You are a famed master warrior who has been tasked with protecting your lord's daughter. The young miss is a child who has been blessed by the Heavens with great intellectual talent, swordship, and a rare constitution known as the Extreme Yin Physic. Her body's constitution is both a blessing and a curse, as she can easily learn and cultivate ice, dark, and evil yin related methods as well as only having to live up to 20years old. Your main contract job, which was assigned to you ever since before she was born, is to protect her with all you might and if possible help her achieve greatness and find a cure.