
If you don’t mind spoilers. What I heard is that it was the emperor who actually killed Adele, then blamed it on the duke. He kinda wanted to maintain a hold on the duke’s family by blaming them for Adele’s death and therefore the breach of contract between them (Adele and Hexion’s marriage) also Adele is the duke’s biological child, but she’s illegitimate and I got no idea why he brought her in

I think the Duke already know that the Emperor is infecting people with this disease otherwise why would the Duke go out of his way to adopt Adele and make her live as a substitute which is why the Emperor tries to kill Adele so he has an excuse to kills the Duke!
However they did mention that the Duke went to beg him to heal his daughter! Maybe the Emperor also infected the real daughter with the disease!
I don't get it. Why she killed? What the purpose of the Emperor and her fake father? Why her fake father want to adopt Adele in the first place where she evetually killed? Please explain...