If anyone's wondering. He's not a mob. He's the MC of the sequel game he never played or knew existed while the hero is another transmigrator/reincarnator who has never played the games. It's when they finally have an honest conversation that he discovers that fact. So he acts as though he's just a mob, but also makes a big splash and spectacle of how strong he is, obviously throws the entire story out of whack, happens to luckily romance route all the heroines of the second game by accident while also going down the romance route of the heroine of the first game, all while hoping that the Hero of the first game will actually do the romance route, as if expecting that the hero would naturally go through the story in a competent manner completely ignoring that most of his perception of the hero are based on him controlling the hero, so another one of those protagonists who has that disconnect between reality and thinking that just because he's in a game world that it will naturally move forward towards a happy ending, even though he acknowledges that there are bad events that can occur.
Also he becomes very game obsessed, as in focused on grinding and power leveling moreso than harem making. He still gets his harem, it's quite a big harem. But he's a battle junkie first and foremost. If I recall right.
You can read the novel here yourself'
https://storyseedling.com/series/92962/