or maybe he killed her husband himselfff??
That was my thought too. Although i'm not sure yet if the brother only started to turn into a demon after she broke the tomb or before that, and why the devil is missing one of its wings.
Well, john is the devil itself which was created as a form of human because of anette's mother who wanted a male child.
Are the parents aware of this? Is that why the father seems to be disgusted of him?
Only the mother and maybe the nanny knows the truth. That is why the mother and the nanny are super protective to Anette and are rejecting the fact of Anette getting close to John/Johan....
Did johan broke a thumb stone too to prevent her sisters wedding? That is why she woke up with a half eaten courpe? Makes sense since it looked like he was in love with her for a while.
According to her , her mother said they had 3 but only found 1 left. Maybe the other one was broken by her mother but not sure what she would have wish for