Arianne begins as Lua's closest friend and staunch defender, consistently standing up for her against bullies who target Lua for her unique healing power. This ability forces Lua to transfer others' wounds onto her own body, earning her the disparaging title "Fallen Saintess." Arianne's unwavering support provides Lua's primary emotional refuge during this mistreatment.

The narrative shifts when Lua uses her power to heal Commander Garrett's critical injuries from a beast attack, an act pushing Lua to the brink of death. While Lua lies unconscious and vulnerable, Arianne claims full credit for Garrett's recovery, appropriating the recognition. Lua discovers this deception upon awakening, revealing Arianne's previously hidden motivations and true nature. This betrayal profoundly alters their relationship, transforming Arianne from a perceived loyal ally into an antagonist whose actions catalyze Lua's subsequent character development and choices.