The problems caused by the changes on the Crown Prince, Ye Qinya, were left for Ye Caoyun to handle by their masters. The reason for this is simple. The two teachers didn't want to handle the crown prince and second, couldn't get involved with the royal family. After all, they are ancestors to the royal clan, once they get involved with them, those people from the palace and even those from the noble clans would overthink things causing commotions that would turn over the whole royal family. Moreover, their influence as ancestors to the crown and as people considered the first like with the purest royal bloodline, they had that much say in the empire.
