Shen Menghui was the current main descendant of the Azure Mysterious Ancient Kingdom. Back then, their heavenly prince was killed by Li Qiye at the dao academy, so they had to choose another successor.
In the end, the young Shen Menghui actually won the spot. He was able to show off his skills among his many senior brothers and sisters. Outside of being the descendant of the Divine Ancestor, it was also because of his exceedingly high talents that were even greater than the deceased heavenly prince.