Precia Testarossa, also transliterated as Presia, is the first main villain of the Magical Girl Lyrical Nanoha series; however, she does not appear in Triangle Heart. A mage and the main resident of the Garden of Time, Precia sends her daughter Fate Testarossa out to Earth to collect a set of Lost Logia (ancient and powerful magical artifacts) known as the Jewel Seeds, while evading the Time-Space Administration Bureau. While a researcher of familiars, she does not have one of her own during Magical Girl Lyrical Nanoha, and her weapon is unnamed.
Precia lives in a gloomy hideout in the Garden of Time with Fate and Arf, although the latter two generally "live" in their apartment in Uminari City more than the hideout itself. Precia spends the entirety of the series in the Garden of Time, and always transformed, except in flashbacks. She used to be a scientist involved in many areas of research, including the creation of familiars, but had another secret, forbidden project.