Sebastian Michaelis (セバスチャンミカエリス Sebasuchan Mikaerisu) is the butler to the Phantomhive household. He was once the servant to Ciel Phantomhive but soon was passed on to Yuki Phantomhive. He saved her from freezing and dieing of influenza and became her caretaker. However he soon dissapeared only to appear 9 years later in time for Yuki's 15th birthday, his whereabout since then were unknown. Sebastian is known for using the phrase, "I am a demon of a butler..." which is used as his main catch phrase for himself throughour the series.
Fashioned by Ciel to look like his late father Vincent, Sebastian is a tall and very handsome young gentleman with black hair and red eyes. He typically dresses in a black waist coat where he sports a silver pocket watch and the Phantomhive crest that the head bulter is to wear. He wears white gloves to hide his Faustian mark that he had when with Ciel Phantomhive, but now his mark that makes him Yuki's is in the center of his chest like Yuki's.
When in his demon form his hair becomes longer, his eyes gain a slitted pupil like a cat's and his fang become sharper. He also has the ability to turn into a black cat when he wishes though he only shows his transformation to Yuki whom is the only one who can tell him apart from other cats.
Sebastian is a dutiful butler and servant to his master, Yuki, and goes beyond the call of duty to make her happy. Though no one is really sure what his feelings for her are he claims he loves her and would do anything to please her. He is often seen kissing her secretly and even doing it a night when she is alseep. He can be strict and hates to be late or be behind schedule causing him to be angry and impacient at times. He also shows a side that is very sadistic and seductive as when he was ordered to take down Juliet, taking his time to hurt her to a point she begged for mercy. Sebastian one side to him that only Yuki and cats are open to feel, he is known to take in stray cats and pet them and play with them, this he also does with Yuki much to her embarressment when he calls her his "cute little kitten."