A new world created by a bored God.
A world where strength rules and every species fight for survival. Before entering the Abyss, species are each put in a separate buffer zone, The Otherworld, where they learn to adapt to the Abyss. The more knowledge about the Abyss is spread among the species, the faster the spread of the Abyss which will in turn cause the time in the Otherworld to shorten. Humans believe that the dimensional walls that separate the Seven Zones will reduce the butterfly effect as much as possible since the lower zones being affects was low since they couldn't see it from above.
In the Abyss, people will start off on the first floor and can go down to deeper floors (similar to going down floors in a dungeon). The first floor is the least dangerous and it gets more and more dangerous the further down the Abyss you go. It is suspected that it is called the Abyss because you could go down forever (there is no end). In Hansoo's previous incarnation, he had already gone down very deep into the Abyss, much further than Elkadion, until he met dragons and other extremely strong creatures of the Abyss.
The Abyss has an extremely harsh environment in which one would need to protect themselves by using skills. It is as harsh as a sea of lava. There are places where meteors fell and places where lightning struck down every time one took a step. Some places don't have any air and others have gravity several tens of time stronger than normal. In the first timeline, everyone below the purple zone were killed when the Abyss occurred.