This novel should be called "The Ring Spirit of the World King". It was about the protagonist Mo Zi Qi being transported to an unknown world because of a self-comforting wish. There, he saw everything that did not exist in reality. At the same time, the rusty ring he wore was an ancient immortal artifact called the Ring Spirit, and he was called the World King. The school ranked people according to their fights, and behind the school was a black hole. I hope you like this fairy's recommendation. Muah ~😗