The tale of a inhuman-human girl: Phoenix

This is the story of a young girl who looks human but isn't. How does Damon know her? How does she know all about his past? What is she? why is she in Mystic falls? Why does Damon listen to her? and is Elena jealous? What is doing at Mystic High? Is she trouble? what is she hiding behind her snarky attitude? Read to find out. (The summary might be crappy but try out the story.)