The new world, selected for the Trial of Gods, was the world that was inhabited by multiple species. However, most prominent amongst them were the Demons.
The world didn't have the Sun, which was why it was mostly dark. However, thanks to the magic, there was light at places.
The Demons and the Humans lived together in the world, working with one another for the most part. It was the usual norm for this world and no one found it odd. There were no large-scale fights between the two groups.
While the Demons were considered the Warrior Class because of their strength, the humans were mostly the business and merchant class of this world. Despite that, there was no concept of money in this world.
A few young gods, who had just turned adults, were sent to this distant world as part of their trials. And this was what started it all.