Lua possesses a unique healing power requiring her to transfer others' wounds onto her own body. This defines her existence and causes significant personal suffering. Misunderstanding or devaluing the cost of her gift, others in her community label her the "Fallen Saintess" and subject her to consistent bullying due to her visible injuries. Despite this mistreatment, Lua finds solace and strength in her close relationship with her best friend, Arianne, who consistently defends her against ridicule and hostility. Lua also holds romantic feelings for Commander Garrett.

A critical event occurs when Commander Garrett faces mortal injury from a beast attack. Lua intervenes, healing him by transferring his near-fatal wounds to herself, pushing her to the brink of death. Regaining consciousness after this sacrifice, Lua discovers Arianne has claimed full credit for Garrett's recovery. This calculated deception reveals Arianne's true nature and motives, shattering Lua's trust and plunging her into profound emotional devastation. Feeling utterly betrayed and isolated, Lua is left without recourse.

Her desperate situation creates an opportunity. The second prince approaches Lua in this vulnerable state. Recognizing her pain and disillusionment, he presents a specific proposition centered on retribution against those who wronged her. Lua accepts the prince's terms, marking a decisive turning point. She consciously abandons her former identity associated with sainthood and healing, signifying a fundamental shift. This rejection initiates her new existence dedicated to enacting vengeance. She transitions into a self-identified villainess, actively pursuing payback guided by the prince's influence.