Mortal Realm Edit
The Demon Beasts destroyed Blackrock City and took control of the Outer Seas in place of the former human alliance named after the island where their headquarters were located, Wondrous Depths Island. Then the demons alliance started to wiped out human villages and hunt the many remaining human cultivators. It was said that after a short time, mortals in the outer seas had been nearly wiped out, and a majority of the cultivators had fallen as well. Fortunately, there were a few islands far from Wondrous Depths Island that the cultivators were able to settle on and hide away. Wondrous Depths Island thus became an outpost for high grade demon beasts.
Spirit Realm Edit
Beast Torrents occured when ordinary Demon Beasts would reproduce in too great a number. Since high-grade individuals couldn't interfere as a result of the agreements, every period of a few years, the demons and humans had no choice but to slay one another to protect their own lives.