Patchouli Knowledge is a character from the Touhou Project series, known for her role as the librarian and magician residing in the Scarlet Devil Mansion. She is a powerful and wise magician, specializing in elemental magic. Despite her immense knowledge and magical ability, Patchouli often suffers from poor health, which limits her physical activity. Her quiet and introverted nature makes her a mysterious presence within the mansion. Patchouli plays a supporting role, providing guidance and magical support to the mansion's residents, particularly her close friend, Remilia Scarlet.