Nine Fates and One EXTRA in cultivation game

A normal guy in his late twenties dies and gets reincarnated in a game as an extra who dies in the backstory , he played the game for years , knows the complete plot , side quests , hidden treasures that can make him over powered , determined to live a happy life again for the second time starts smiling and walk towards the protagonists to change their plot to what he likes daily one chapter none of the 9 protagonists will be " a guy who starts out small , gets a harem , becomes invincible etc " all nine of them will be of different age groups and none will have a harem and mc will also not have one ( there will be romance but no harem ) , it's my first novel so if I make any mistakes please comment, if it's going too slow please tell me thank you