Lady Syl was the former Dark Lord's daughter and once had a loving relationship with the current Dark Lord, Jin, who served as a student under the former Dark Lord. However, Jin was forced to kill his mentor after the Balrog possessed him and all attempts to reach out to the former Dark Lord's spirit failed. Saddened, Jin returned to bury the former Dark Lord and took it upon himself to work as the next Dark Lord.
However, the Balrog claimed another victim; Syl, out of anger, accused Jin of not protecting her father and even believed that Jin engineered her father's death so he could claim the title of Dark Lord. Jin tried to persuade her, but she vowed vengeance and promised that her new rival will die before leaving. As a result, Lady Syl formed the Dual Blades.
It is only until a disciple of her steals the Dark Lord's diary, detailing of what truly happened to her father, that causes Lady Syl to hesitate on her actions and rethink. She reluctantly decides to cease her desires of revenge and reform an alliance with the Dark Lord, as well as the rest of Maple World.