
Their father has beaten and abused Cesare since childhood pretending it was love since he wants to use him. Cesare treasures Ruby but ends up beating and abusing her thinking it’s love because he wants to hold onto her. He hates their father and winds up becoming just like him, though we don’t know at this stage if he’s realized that and is fine with it as long as he can keep Ruby or if he thinks he’s only doing it because he has to.
The first time Ruby rejects a marriage their father talks about throwing her away and Cesare reacts very poorly to it (and also heavily implies that the girls in the convent she would be sent to are either physically or sxually abused, so how could they send Ruby there) and the dad basically threatens to beat him again. It’s after this and ‘Ruby’ forgetting ‘their promise’ to live together forever that Cesare starts getting physically violent with her as well to get her to comply, probably thinking it’s better if it’s him ‘disciplining’ her rather than their father (who previously sent child Cesare to the dungeon to get beaten by multiple men for speaking back at him).
TLDR; dad mentally and physically abuses Cesare since he’s a kid. Cesare then ends up mirroring that mental and physical abuse (less extreme and more personal, which is a different type of horror for Ruby…) onto Ruby, who he has internally designated as the light in his life he is terrified of losing. Ruby is an x2 victim (and current Ruby probably doesn’t even remember the promise Cesare is holding so dearly), Cesare is a victim to his dad and an abuser to Ruby. Cesare started physically beating her after she rejected her third marriage. That’s it o7
Id read this but it has cesare in it
Feel free to summarize it