The ancient Celestial Prison, the Monster Realm of today, can be said to be the closest large world to the present world,
as the new world birthed by the Ancient Demon Emperor breaking through the Chaotic World. Even after long evolutions, it still can't completely shake off the threat of Chaos.
Despite countless Heaven Demon Dharma Altars illuminating here, even shining through multiple eras, it still harbors many dangerous places, like irreparable scars of the Monster Realm, preventing this world from fully connecting and flourishing like the present world with countless miles of civilized fertile land.
In the Monster Realm, natural barriers like Frost Wind Valley are not unique. From another angle, they have extended the wars between humans and demons over several eras, leaving many buffer zones.
In places without natural barriers, humans and demons build large cities and confront each other, battling endlessly.
