In the end, Fang told Ren that he would think about it and decide later what he wanted to do about his legacy from two royal families.
And, Fang had to admit, he was looking forward to meeting the Dragon Queen, who he now knew to be his own paternal aunt, and his big sister and his cousin brother. How nice it would be to have a family of his own, to have some relatives of his own! Wasn't that the dream of every orphan?
All in all, Fang's joy at finding some decent family members on his father's side overrode his distress at finding horrible beasts on his mother's side of the family. Besides, he had Ren acting like an avenging angel by his side, so Fang simply continued with his plans for the perfect party he wanted to throw for Ren and pushed everything else aside in his mind.