Precia Testarossa, also known as Presia, is the primary antagonist in the Magical Girl Lyrical Nanoha series. Despite not appearing in Triangle Heart, she is a mage who resides in the Garden of Time and sends her daughter Fate to Earth to gather Lost Logia artifacts called Jewel Seeds. Although Precia does not have a familiar of her own during the series, her weapon remains unnamed. She first emerges in episode 7 as an abusive and cruel figure who tortures Fate for failing to collect enough Jewel Seeds and eliminate potential hindrances like Nanoha. Despite Arf's dislike for Precia and his advice that she is not worth it, Fate believes that her mother will be cured of her insanity if she gathers the Jewel Seeds.
Precia resides in a secluded hideout within the Garden of Time with Fate and Arf. Although they often dwell in their apartment in Uminari City, the hideout serves as their primary residence. Throughout the series, Precia remains transformed and spends her time solely in the Garden of Time, except for flashbacks. Prior to the series, Precia was a scientist who conducted research on various topics, including familiar creation. However, she harbored a secret, forbidden project that has yet to be revealed.
Precia defeats their first group of soldiers and, realizing that Fate is among those observing her in the Arthra, reveals that Fate is a clone of her biological daughter Alicia. Precia went insane when Alicia died and concentrated herself on her secret project, which researched both cloning and the forbidden art of resurrection: Project Fate, from which Fate Testarossa takes her name.
Late in the series, Arf finally strikes out at Precia, and is thrown out as "useless". Precia supervises Fates winner-takes-all fight with Nanoha, and when Fate loses, sends a storm to attack Fate and steal her Jewel Seeds before she can give them away. The Time-Space Administration Bureau, having joined up with Nanoha and labeled Precia as a dangerous criminal, traces her to the Garden of Time and attempts to capture her.
Late in the series, Arf finally strikes out at Precia, and is thrown out as "useless". Precia supervises Fates winner-takes-all fight with Nanoha, and
In the movie it was revealed that Precia was always busy with work and never had time for her daughter. She had promised that the two of them would s
She also reveals that Fate was a temporary replacement, a tool to get the Jewel Seeds so that Precia could go to the ancient capital of the magical worlds, Al Hazard, and retrieve the lost technology that could finish her work.Precia activates the nine Jewel Seeds in her possession and wishes to go to Al Hazard. This action causes a massive dimensional disturbance, and the Garden of Time begins to fall apart.
When Fate joins up with Nanoha and the TSAB forces, she attempts to save Precia, but the crazed mage refuses, laughing in her face and choosing to die with the preserved body of Alicia rather than face a several-hundred-year sentence for her crimes. In the end, she falls without a struggle into a dimensional void.
In the movie it was revealed that Precia was always busy with work and never had time for her daughter. She had promised that the two of them would spend time together before Alicia started school. But durring an experiment Alicia died driving her mother mad with guilt. As she falls to her death she remembers Alicia saying that she always wanted a little sister and thinks to herself "I never notice things until its too late."