Overlord: Demon King

It was the year 2138, and the world was but a shadow of its former self, a mere decrepit corpse to a once prosperous planet.
But the world still followed the fundamental law of equivalent exchange and as there was still humanity, there had to be prosperity.
But such a thing had become quite rare in the real world, which was the main reason for the creation of DMMOs.
YGGDRASIL...he was quite fond of that game.
It was his prosperity...yet...
It seems to be the new reality.