Florence Nightingale manifests as a Berserker-class Servant under Ritsuka Fujimaru's command during the Grand Orders. Her identity draws from the renowned 19th-century British nurse who transformed nursing during the Crimean War. Defying her affluent family's strong opposition to the then-lowly profession, she pursued nursing, mastering advanced medical techniques in Germany and reforming London's nursing systems before managing nurses in Crimea. There, she confronted horrific sanitary conditions and outdated medical regulations head-on, using her personal funds to implement reforms that slashed mortality rates from nearly 40% to 5%. Though soldiers revered her as the "Angel of Crimea," she rejected the title, viewing herself solely as dedicated to saving lives. Post-war, she relentlessly advocated for medical reforms, championing statistical analysis of records, military healthcare improvements, and the founding of nursing schools—her legacy culminating in the enduring "Nightingale Pledge" oath. Her manifestation as a Berserker stems from her extreme conviction that saving lives can necessitate taking lives, a philosophy perceived as madness that grants her EX-ranked Mad Enhancement. This amplifies her persistent, uncompromising nature. She recognizes her Master only as the "commander of her army," rarely engaging in dialogue, often speaking to herself while obsessively prioritizing sanitation, nutrition, and injury prevention. Visually, she wears a 19th-century British Army uniform: a black skirt with red trim. Her platinum blonde hair is long and braided, her eyes red. In higher ascension stages, she carries medical supply bags, a rotary pistol, and a black coat draped over her shoulders, with bandages covering the right side of her face. Her abilities mirror her medical expertise. "Understanding of the Human Body" enables instinctive, precise targeting of vital points and damage reduction. "Nurse of Steel" allows her to heal grave injuries using magically conjured scalpels and medicines, drawing power from anecdotes of those she saved. Her Noble Phantasm, "Nightingale Pledge," heals allies, removes debuffs, and reduces enemy Noble Phantasm damage, later upgraded to also halve enemy attack power. Paradoxically, she opposes magecraft for healing, deeming it occult and ineffective. Across official narratives, she appears consistently. Suffering amnesia in the "Prison Tower" event, she is nicknamed "Mercédès" by Edmond Dantès, who links her to his lost love; she persistently seeks to treat his psychological wounds despite his evasions. In the "E Pluribus Unum" singularity, she initially prioritizes treating wounded soldiers over Chaldea's mission, joining only after concluding resolving the singularity would save more lives ultimately. During the "Grand Temple of Time: Solomon" finale, she fights alongside Servants like Nero Claudius, Francis Drake, and Bedivere against Demon God Pillars and Goetia until unsummoned. She perceives all Servants as "soldiers" needing nursing care. Opponents are "enemy soldiers" to be saved through incapacitation, even if lethal force is required. She exhibits particular concern for mentally unstable Servants like Dantès, Caligula, and Salome, insisting they require psychological treatment regardless of their resistance.