Spoiler
Cosettenis actually his child but she died when she was born and before the delivery of the child, former duchess made a contract with the demon so now there is demon in consette body. It I strue that former duchess was framed by the current duchess family. I have heard that Duke knew that kiera was the real one but just because everyone said she was fake so he decided to stay neutral. He just doest deserve forgiveness at all. But why the author made him damn handsome that even if we want to, we can't come to hate him at all. So I will simply not forgive him
to be honest, i have a soft spot for parents, specially when they're beautiful. I think the current duke doesn't know how to love properly, maybe? since i think it was mentioned that all grand dukes stayed neutral? well he is kinda a bitch for not speaking up. He must've regretted it tho? since he turned back time and all. It might be hopeless, but im still hoping keira and the duke fix their relationship. As i said, i have a soft spot for parents.
I hate him and the only reason I can hate him is because I've seen other hot characters that aren't as big of an ass like him (〜￣△￣)〜
omfg
i think that the grand duke has always stayed distant bc he is the head. he actually loved keira but didn't realize it. That's why the father never blinked when everything happened but started to regret it once she died. He made the magician turn back time becausekf the regret. H emay or may not have realized cosette's schemes. and most likely, cosette is actually the second daughter. its shown in that diary that the YOUNGER awakened first and onlu after a few years after resonance did the eldest gained her ability.
i personally hate cosette but maybe there was a scheme to why her mom was said to never had a child. im thinking that this is related to Keira's granddad.