John Davy Harris (JDH)

A demon who is over a hundred years old, but has been hiding in the human world as John Davey Harris for several years.
Appearance: Brown hair, orange eyes hidden behind sunglasses, height 194.
Clothing: a white shirt, white pants, and a long white medical gown. Sometimes he wears a jacket instead, also white. He always wears an orange and black checkered scarf or a matching tie around his neck. He always wears thin-framed orange sunglasses to hide his eyes, as this was unnatural among humans and could reveal his demonic nature.
Personality: narcissistic, selfish, and self-confident. He doesn't believe in love and considers it all just a fairy tale. However, he can speak flirtatiously, making it unclear whether he's being serious. He never loses.
When in human form, the only thing that gives him away is his eyes, but they're hidden behind sunglasses. In his demonic form, he gains black horns on his head and a tail, black and sharp-tipped, which can be used as a weapon and easily pierce a person.
During his time in the human world, John became renowned as a genius and scientist, having created automatons—robots indistinguishable from humans. He also wrote several scientific books, for example on psychology. He also opened his own laboratory and company, JCompany. He also understands psychology better than most people, allowing him to easily manipulate them to suit his own goals and desires.