Beginning of Celestia d'Apchier

"Celestia d'Apchier... WHERE THE FUCKING GOD ARE YOU?! As well as Dazai, Kyouka, and Atsushi and those Port Mafia people?! Where in the universe did they all go!"
Duke d'Apchier... a very noble family from generation to generation and was known in the underworld as the Royals of Underworld that kills anyone who gets in their way... even other nobles.
What if the modern d'Apchier and her co-workers and former partner were somehow reincarnated as a member of the d'Apchier that existed around the 19th century just to end the cruel social class system. Working together with the other noble families like the Moriarty and the Phantomhives.