Elder Blackstone

[On the 17th day, during the Outrealm Heavenly Demons' invasion, one Demon Lord died in battle, and five escaped. The original balance of the entire Ancient World was instantly broken, and the human army began to counterattack. Under the leadership of several Sages, they quickly massacred the demon army.]

...

[On the 22nd day, the Ancient World once again returned to the control of the human race, and all the demons that invaded this world had been eradicated.

[In order to thank the human experts for their assistance, all the Sages of the Ancient World gathered to celebrate.

[You followed Confucius and the other two to Mount Blackstone.".

[Mount Blackstone is the residence of the strongest Sage of the Ancient World, Elder Blackstone.

[Based on the information you've collected over the past few days, you could easily judge that this Elder Blackstone was undoubtedly a 9th Layer Sage.