Leila, an infamous female assassin who has lived her life embraced by darkness was killed by an explosion that was orchestrated by an enemy who also murdered her sister. Driven by rage, she swore a blasphemous oath and had opened her eyes once again to find herself in the body of the heroine's older sister. Who happens to be same Liese of her past life. However, there was a new enemy who threatens everyone she cared about. So, Leila prepared herself to her biggest, most dangerous undercover mission yet. One where she would become the greatest villainess the world has ever seen.