The Cursed Strongest Player Rules The World summary:

In the popular VR Net game “Deep Space Frontier,” set in a world where humans, angels, demons, and beastmen exist together, the world is engulfed in chaos due to the threat of the powerful Demon King, Sada. Among the tens of millions of players, heavy user Zen Ichinose is the only one to successfully defeat him! However, his victory is short-lived as he is engulfed by light emanating from his monitor and drawn into the game world. Furthermore, his appearance is that of the Demon King Sada himself, whom he had just defeated…?!