The moment he saw Zhu Ju, the Mang Mountain Ghost Emperor cast all thoughts of the 'Jianmu' aside.
'The Heavenly Mirror!'
He was the successor to the Fengdu Ghost King's legacy.
Although the Ghost King was not the Fengdu Emperor, he had been fortunate enough to ascend to the Celestial Court and witness the Celestial Emperor's Dharma Aspect.
During the great calamity of antiquity, none of the Immortals and Gods could escape their fate.
A Daluo like 'Taiyin' might have been able to hide in the river of time to avoid the calamity, but the Celestial Emperor absolutely could not.
As the Lord of All Heavens and Myriad Realms, the Celestial Emperor possessed supreme authority, but he also had to bear the most powerful backlash.
Other Immortal Gods might have a chance to be reborn in the current era or choose successors, but the Celestial Emperor had absolutely no such possibility.
But...
The Heavenly Mirror!
