Fate Testarossa Harlaown is a main character in the 'Mahou Shoujo Lyrical Nanoha' series. Initially introduced as an antagonist, she is a powerful mage with a tragic past. Fate is known for her calm, gentle demeanor and strong sense of justice. Over time, she becomes one of Nanoha's closest friends and allies. Later, she is adopted by Lindy Harlaown, taking on the surname Harlaown. Fate plays a critical role in the series, both in combat and emotional development.