so almost everything is like a game he played and no one else has played this game and noticed the similarities? if it was supposed to reference d&d like i think it is then it makes sense that only he and the rest of the players in the campaign would know about it but this is a crazy amount of detail for just a d&d campaign.
So guys, what im thinking is that his ability might have come with some kindd of OP passive that goes all the way in making his life like a game. As in it forces all nearby monsters and dungeons to behave similsarly to the game.