Death Game of Ghosts and Gods

I was locked up in a mental hospital for five years. Everyone thought I was sent in by relatives because of the car accident and my parents' inheritance. I escaped and found the only legacy left by my father, a blood-red nail, and also came into contact with the terrifying secret he had hidden his whole life. Now, a being who calls himself "Ghost" told me: God created the world in seven days, and we will use seven games to change the world. "What are you looking for?" It asked. "Find a... Proof of my existence." My name is Meng Yan. I was once trapped in a nightmare. Now, I will become a nightmare in this world. This is a [game] that belongs to lunatics, perverts, faithless people, and careerists. Here, humanity is wiped out, desires are growing, and the one who survives to the end is not necessarily the winner.