After Pretending to Be Stupid for Three Years, the Engagement Was Annulled, and I Turned on the Ghosts

On the eve of the rebirth of spiritual energy, start by cutting off all opportunities in the future! In my previous life, I was betrayed by my best friend and died before dawn. In this life, I am reborn as an abandoned son of a wealthy family with the memories of the next twenty years. Are they laughing at me for being silly? I backhandedly saved the S-class ghost queen who would be born three years later and made her my personal maid. The villain has been planning for ten years to seize the god-level magic weapon? Sorry, I knew where it was hidden and took it out in advance. What are the secrets of the major exorcist families in the future? Sorry, those are all leftovers from my previous life. While everyone is still exploring the strange laws, I have already taken advantage of the information gap to grab all the opportunities in the world and build my own empire of hundreds of ghosts!