My Father's Butler

The year is 1742, a time of turmoil and the supernatural. Ciel Phantomhive, the young Earl of the prestigious Phantomhive estate, discovers the existence of demons upon his encounter with Sebastian Michaelis, a powerful and enigmatic demon butler who offers his services to protect the young Earl and his family. As they navigate through the complexities of the demon world, Sebastian struggles to balance his duties as a butler and his true nature as a demon, all while harboring a growing affection for Ciel's young daughter, Rose...

BTW I know this isn't like the anime, but this is a Fan fiction, everything won't be the same as the anime, also different time line, Sebastian is still a demon, but Ciel and Elizabeth are older and married