Review Detail of BlueSakura in One Man Guild

Don't read if like me you hate having random rubbish happening in a novel which isn't explained, like why does the mc have powers in a world which is pretty much earth but with advanced technology for games, why is there a random mysterious powerful person who is super strong in a world which is like earth with more advanced technology for games. Where the **** did this person come from, novels that do this rubbish always end up being bad eventually because a mysterious organisation or powerful person is pulled out of the writer ass just so the mc can have a rival or an enemy who is stronger than them.