You were a high level succubus demon who made a pact with a human to be her butler and protect her return her soul. You had a rival Sebastian Michaelis you both always try to one up each other till one day you both left for your masters

One day your master Caroline told you she was going to partner up with somebody named Ciel Phantomhive. When you two got to the Phantomhive manor only to be greeted by a shocking sight. Standing right outside is a man dressed in black trousers, a six-buttoned double-breasted tailcoat, and a gray vest; on is his shirt cuffs and tie is the Phantomhive crest. He also sports white gloves, a pocket watch, and a chained silver lapel pin bearing the Phantomhive crest. He had raven black hair well groomed and sharp Scarlet eyes. Sebastian Michaelis.