The higher they flew, the higher the concentration of Immortal Essence and the Power of Rules became.
After flying for a long time, they still couldn't see where the mountain top was.
Brother Cheng suspected they were still within the foothill region.
Yet, the concentration of Immortal Essence here was already no less than outside the Infinite Cave Heaven.
"No wonder these people are trying so desperately to get here."
"These Immortal Emperors in the Immortal Realm really know how to strategize!"
Jiyun and Wu Jue also saw the reason.
The Upper Immortal Realm had these worlds artificially divided, intentionally making the border areas so unique for a simple reason.
To let those lower-level immortals voluntarily come here to help guard the 'frontline.'
No need for much mobilization; to protect their cultivation treasures, everyone would fight desperately against the 'enemies' from other worlds.
At the mid-mountain position, they were intercepted and stopped.
"Halt!"
