Florette Harvenheit, commonly known as Fiore, is a significant character in Chrono Crusade. Her true identity is that of the eldest daughter of the Harvenheit family, a lineage of jewel witches, making her the older sister of the jewel summoner Satella Harvenheit. At a young age, she was kidnapped by the demon Aion, who killed her and then used his powers to revive her as a servant. As part of this process, Aion erased her original memories and implanted a false personality, creating the being known as Fiore. This new identity was conditioned to believe that Joshua Christopher, another captive of Aion's group known as the Sinners, was her younger brother. Her place of origin is Germany.

Fiore's personality is outwardly calm, quiet, and often appears cold or emotionless. This demeanor masks a deeply caring and protective nature, particularly towards those she considers family. In her role as Joshua's guardian and maid, she is fiercely protective of him and takes her duties seriously, even exhibiting a firm, motherly side by insisting he eat his vegetables. Despite her usual seriousness, she occasionally shows a dry wit or a self-paced side, such as playfully ordering Aion to run errands. She is also an excellent cook, a skill she uses in her role as a caretaker.

Fiore's primary motivation is the protection and service of Joshua Christopher, whom she has been looking after since he was a boy. She has vowed to protect him no matter the cost, and her entire constructed identity revolves around being his sister. Her role in the story is that of a tragic antagonist and a poignant obstacle for the protagonists. She serves as a direct enemy to her biological sister, Satella, whom she does not recognize and fights without hesitation. For much of the narrative, she is a loyal agent of Aion, residing in his group and acting as a formidable fighter on his behalf.

Her most critical relationship is with Joshua, for whom she feels a deep, sibling-like love that may have romantic undertones. This bond is the core of her false identity. Conversely, her relationship with her biological sister, Satella, is one of tragic conflict. Fiore shows no initial recognition or familial affection for Satella and attacks her ruthlessly during their encounters, insisting that Satella's sister died long ago. She also has a relationship with Aion, whom she serves as her master, seemingly without resentment for the fact that he killed her original self.

Fiore's character development revolves around the conflict between her fabricated personality and the remnants of her true self. While she generally rejects her past as Florette, there are moments where her original memories or feelings surface. For example, she once mentioned that a certain food was something her sister liked, showing a faint, lingering connection to her past life. Her tragic arc reaches its peak in her final battle with Satella. In the anime, she is seemingly destroyed, while in the manga, she and Satella are frozen in crystal together for decades, after which she later awakens with the personality of Florette restored, watching over her sister from a distance.

As a jewel summoner from the powerful Harvenheit family, Fiore possesses significant magical abilities. Unlike her sister Satella, who summons spirits, Fiore's fighting style is direct and aggressive, using her magic to create weapons out of jewels, most notably a large, elegant scythe. She is a fearless and efficient combatant, described as cool, polite, and unfailingly elegant even in battle. In addition to her natural magical power, she was implanted with a demon legion, which grants her superhuman physical abilities and a potent regenerative factor, allowing her to heal from severe injuries.