In Xuan Country, there is a dangerous land called Hundred Beast Mountain, which is located within the northern mountains of the country. This area is seldom visited by humans due to the mass of demon beasts that roam there.
This area was once the epicenter for a demon beast uprising, which resulted in the destruction of several nearby cities. As a result, a thousand-mile radius surrounding the Hundred Beast Mountain was sealed by the mighty spell-casters of the Xuan Country using an ancient array. This seal prevented the demon beasts from escaping, condemning them to perpetual confinement.
Simply put, Hundred Beast Mountain is a massive cage specifically designed for demon beasts.
The seal on the Hundred Beast Mountain has been in place for hundreds of years and has never been lifted. Only the current emperor of Xuan Country had dared to venture into the mountain when he was a youth and managed to come out alive.
