why blame her for his impotency

hi,
got my niece married off with lots of fanfare. after two years of derailed life of hers we found that the guy suffers from ED. dodged her for long time by not getting her visa to join him. always created tension in life and made the world to listen his stories. the worst is that he always wished to share the intimacy with his wife to his friends and relatives but the fact is that make her rigid so that she does not come close to him and realize that he is impotent. the worst and poor situation is that he made all his family members too to believe that he is right but the fact got exposed through a common friend that he is totally a failure and is inadequate, suffering from ED and non attraction towards women.
1. why should he get married in the first part - cant he tell his parents that he is not attracted towards girl
2. it seems with the instances that his parents are aware of his impotency and they also acted smart by hiding the facts
3. after finding the facts they say a mutual settlement is preferred by them but without any financial support - maintenance - alimony or whatever
4. where is the vow dumped during the course of marriage taken
5. if fraud is the main motto then who is to be believed - horoscope / mediators / well wishers or thy almighty

please advise
1. should he be not sued for the intentional fraud
2. if he does not come for mutual consent for divorce and settle the matter
    what should we do
3. god has since punished him, but he seems to be a sadist, what can
    we do to get him to books

please.........................