Not a legal advice – but the girl and her family should take a stand for herself and straight up deny marrying the guy. You shouldnโt take a powerful person head on for someone who you just met. Who knows if they back down and go with the person, your friend will lose money and make a new enemy.
Ask him to verbally acknowledge to the guy that he has backed off, let the guy reach the girlโs family. Let them deny him. After a couple of months go ahead and get married.