It had been nearly 2,000 years since the founder of the Celestial Pole Sect established the sect on Dongting Mountain.
The Supreme Elders of each generation had guarded the Demon's Den for so long, and they had encountered demonic energy surging up, but not a single demonic creature.
Not to mention the terrifying Ancient Demons.
As such, there was a high chance that there were no Ancient Demons or demonic creatures in the Demon's Den.
The founder of the Celestial Pole Sect was most likely guarding against the leak of demonic energy.
It was unknown how deep into the ground the Demon's Den was. If there was remnant devil energy inside, it wouldn't dissipate on its own as time passed. Instead, as time passed, the more they would fuse together, making it difficult to eliminate.
Therefore, Wu Qifen and the other upper echelons of the Celestial Pole Sect were wary of the demonic energy.