Saiai no Onee-sama ga Akuyaku Reijou datta no de, Kami ga Sadameta Scenario ni Aragaimasu - Vol. 3 Ch. 15

[MangaDex]

 

[Epic_GamerXD]

She became what she really wants to defy.

 

[jrocker]

So Oswald's backstory is that he is a terribly selfish and arrogant thing, was always a terribly selfish and arrogant thing, and had something bad happen once and became even more terribly selfish and arrogant... Given they showed he would "listen" to his mother's scolding he clearly never took them to heart since he did it constantly and then with her gone did it more and worse. The rest of the family and staff suck for never actually punishing him when everyone can clearly tell that was what he wanted.