When Patchouli uses Philosopher's Stone, she's actually calling Mokou, Nitori, Aya, Iku, and Suwako to assist as her familiars.
Patchouli as a result is the owner of a yakitori stand, giant robot/nuclear facility, a newspaper, and a mountain-top shrine. She also holds favor with the dragon gods, which is how she managed to become such a powerful magician at such a young age, despite physical disabilities.