Jiuli Mountain, not only is it the source of the Hidden Dragon River, an eight million mile long river, but also the largest Nether Ghost Zone on the Phoenix Continent, inhabited by billions of Soul Ghosts!
Several tens of thousands of years ago, this place was originally a Blessed land of the Immortal Realm, with innumerable immortal and mortal beings, until one day a sudden disaster struck, with endless ghostly Qi pervading and wreaking havoc, changing the color of the heavens and earth, causing Jiuli Mountain to completely fall into a Ghost Zone.
The sudden rise of boundless ghostly Qi, with unknown cause and origin, turned the mortal realm into a Ghost Zone in a very short time... It is a manifestation of eerie Evil Spirits, essentially the Residual Resentment of a decaying world's "Heaven's Will" affecting the normal world, even the Universal Realm could not avoid it.
