
So the Duke cheating on his wife with Camilla's mom... I'm so disappointed

Technically he did not. He has amnesia while he's with Camilla's mom. Then suddenly regained his old memories and lost his memory when he was with Camilla's mom.
That is why he thought he lost the red ring (Camilla's ring from her mom) and didn't know that he gave it to Camilla's mom, since he lost his memory of that period/timeline.
He regained his memory before Camilla's mom noticed that she was pregnant with Camilla.

I don't think so. I can't remember the timeline of how the parents (all of them coz wtf are they doing) just friggin planted seeds but his eldest is adopted. Then yeaaars later lil bro is born. I don't think he was married yet when he met Camilla's mom. I honestly don't remember those finer details tho

Diana is the kind of person who believes that '' either she's right or everyone else is wrong '' if you agree with her, you're a righteous person but if you don't, then you're evil who deserves God's punishment.
Regarding her condemning Kael for the murder of that family that threatened her: if she truly believed that he was wrong, she wouldn't have taken advantage of the situation and marry Helios. She would have refused to become the CP a position that came from the murder of someone else. But no, she choose to overlook that, threw herself into a position bigger than what she could handle then when things didn't go her way she blamed everything on Hestia.
It's true what Helios said that Hestia doesn't really care about what's right or wrong but if you look at what she's accomplished, especially for the common people, you can't blame her. She's just outsmarted Diana and Helios and made her territory a better place in passing
Guys I need to know what happens in this conference please if you know any spoilers I will gratefully accept