I, a Pure Passerby, Am Forced to Play the Protagonist and the Villain

I, Yu Nianliang, traveled through a world in a book with the Dragon King, the God of War, the Miracle Doctor and other children of destiny. However, I am neither the protagonist nor the villain, but a pure passerby who does not deserve a name! Protagonist, villain, you fight your battles, don't get involved! I suffered in my previous life, but in this life, I want to be a rich man and enjoy myself! Wait, dog system? You want me to steal the Dragon King's woman? Are you going to disrupt the marriage of the villain's family? Do you want me to build a business empire? No, I just want to be a happy rich second generation. Protagonists who have been ruined in various ways: Why do I feel like my luck has been stolen? Villains who have been defeated by all kinds of villains: The protagonist obviously hasn't exerted his strength yet, why am I gone?