TV-Series
Description
Originally named Fate Testarossa, Fate T. Harlaown is an artificial human created by Precia Testarossa through Project Fate as a clone of Precia's deceased biological daughter, Alicia. Raised in isolation within the Garden of Time, she endured physical and emotional abuse while being manipulated into collecting Jewel Seeds for Precia's goal of resurrecting Alicia. During the Jewel Seed Incident, she repeatedly clashed with Nanoha Takamachi, who sought her friendship. Learning her origins as a clone and facing Precia's rejection led to her rescue by Nanoha and the Time-Space Administration Bureau (TSAB). Precia's death during the Garden of Time's collapse resulted in Fate's trial and subsequent acquittal, recognizing her actions were coerced.

Adopted by TSAB Admiral Lindy Harlaown, she changed her surname to Testarossa Harlaown. Six months later, during the Book of Darkness Incident, Fate joined the TSAB as a contract mage. Partnered with Nanoha, she helped resolve the incident involving Hayate Yagami and the Wolkenritter. Her Intelligent Device, Bardiche, was upgraded to "Bardiche Assault" with a cartridge system to counter Belka-style weapons. This period solidified her partnership with Nanoha and her integration into Earth's civilian life, attending school alongside her.

A decade later, Fate became an elite TSAB Enforcer, holding the rank of 1st Captain (equivalent) and S+ mage certification. She served as Executive Officer of Riot Force 6, leading the Lightning Unit under callsign "Lightning 01". Her duties included training new recruits, notably her adopted wards Erio Mondial, a fellow Project Fate clone, and Caro Ru Lushe, an exiled dragon summoner. Confronting Dr. Jail Scaglietti, creator of Project Fate, during the JS Incident revealed his Relic-related experiments. She co-adopted Vivio Takamachi with Nanoha following Vivio's rescue, forming a multi-generational family unit with Erio and Caro.

Personality-wise, Fate is serious, strong-willed, and deeply protective. Early experiences left her questioning her self-worth, though she gradually embraced her identity separate from Alicia. She prioritizes preventing child exploitation, focusing her work on cases involving young victims. As a parent, she exhibits greater permissiveness and heightened protectiveness compared to Nanoha, often rushing to comfort Vivio after minor accidents. She maintains a reserved demeanor but displays shyness and blushes easily. Her combat style evolved into a "Fragile Speedster" approach, emphasizing high-speed maneuvers with Bardiche, which shifts between scythe, sword, and ranged forms.

In later continuity, Fate and Teana Lanster served as Enforcers in Hayate's Special Duty Section 6, investigating the Eclipse Incident (Bible of the Silver Cross). She maintained her role as Vivio's godmother and legal guardian to other children like Lutecia Alpine during transitional periods. Her relationship with Nanoha evolved into a confirmed romantic partnership, co-parenting Vivio within the Takamachi household.