Just as the Supreme Unity experts do not wish for more Quasi-Saints to emerge, Saints also do not want another peer-sharing their level of sanctity.
Although the Six Saints can prevent other Quasi-Saints from advancing, they can't stop Hao Tian.
That's because Hao Tian's backing is Cultivation Path Ancestor.
As long as the Cultivation Path Ancestor allows it, unless the Six Saints tear off their masks, no one can contend with the Cultivation Path Ancestor.
This seventh saint position, in terms of strength, background, and tactics... in all aspects, Hao Tian is essentially guaranteed to secure it.
Most importantly, Hao Tian has the closest relationship with the Cultivation Path Ancestor.
Hence, Divine Lord Xuanwu has always believed that becoming a Saint is not that difficult for the mentor.
Furthermore, it's now quite evident that there are stronger and weaker among the Saints.
Thus, the mentor's goal is probably not just to be a common saint.