TV-Series
Description
Within the world of Petals of Reincarnation, F. Nightingale is a prominent member of the Forest of the Greats, an organization composed of Returners who have awakened the abilities and talents of their historical past lives. Her role within this group is primarily that of a healer, as she is responsible for the medical treatment of all its members.

In terms of her outward presentation, Nightingale is a lady of grace who appears in a nurse's uniform, a visual cue to her Florence Nightingale incarnation and her function as a caretaker. She carries an air of quiet mystery, largely due to her eyes being perpetually hidden behind her bangs. Her apparent demeanor is often described as motherly and calm; she does not speak much, which contributes to her enigmatic presence. This gentle exterior, however, is a deliberate facade. Those who observe her closely, such as her colleague John V. Neumann, note that her methods of healing are unusually intimate, leading her to be nicknamed the Naughty Nurse for her tendency to make excessive physical contact with her patients during treatment. This eccentricity in her healing process is the first hint of a deeper, more unsettling truth about her character.

Beneath the composed surface, Nightingale possesses a profoundly different true personality. It is eventually revealed that the individual known as F. Nightingale is an imposter who has stolen the body and talents of the original Florence Nightingale, the White Person, for her own purposes. The real Nightingale appears to have died or been displaced, leaving this entity to operate under her identity. In stark contrast to her public persona, this imposter is sadistic, dominating, and prone to chaotic, manic laughter. She is driven by a desire for conflict and entertainment, seeking to fight powerful opponents and seemingly treating the organization's grand plan as a pretext to turn the entire world into her enemy. This makes her one of the more dangerous and unpredictable figures among the Returners.

Her motivations are complex and tied to a long-term scheme. Deeply involved in secret experiments on Returners and the nature of the petals that grant their powers, she has been manipulating her allies for years. Her healing talent, Angel of Healing, serves not only to mend wounds but also as a tool for a subversive long-term plan. By healing even minor injuries over a prolonged period, she has been able to gradually exert control over her subjects, a secondary ability known as the Crimson Red Shadow. Furthermore, her experiments led to the creation of Albert, a being with the talents of Albert Einstein, further demonstrating her willingness to manipulate lives for her own ends. Her actions are a major driving force behind the central conflicts of the story, as her true nature and her Greatkind Plan are revealed to be a pretext for her personal amusement and ambition.

Her key relationships are built on this deception. She maintains a close working relationship with Hiroshi Funasaka, a combat operative of the Forest of the Greats. Their interactions, characterized by her indecent way of healing him, are so unusual that other characters mistake them for a romantic couple, though this is merely one part of her act. She is also connected to Nikola Tesla and the being Albert, both of whom, for their own reasons, choose to assist her even when aware of her true nature. These connections highlight her ability to manipulate powerful individuals for her own inscrutable goals.

Development-wise, the character of F. Nightingale is defined by the dramatic shift from a nurturing healer to a primary antagonist. As the story progresses, her initial role as a background support for the Forest of the Greats gives way to a central antagonistic force. The revelation that she is an imposter and a sadistic mastermind completely recontextualizes her earlier actions, transforming her from an eccentric ally into a major threat whose ambition is to create chaos on a global scale.

Notable abilities include her primary talent, Angel of Healing, which allows her to restore the wounds of any Returner. This is combined with her secondary talent, the Crimson Red Shadow, a more sinister skill that allows her to subjugate and control individuals she has healed over a long period. Beyond these, she is also known to have stolen other talents from various sources, making her arsenal of powers unpredictable and extremely dangerous. Her most significant act of manipulation involves the stolen body and identity of the original Florence Nightingale itself, a deception that lies at the heart of her power within the story.