phenomen a book

A man that has turned his life around dies and is brought back as a student that was put into coma but this world is not the easy going one that most people would think it is, the world is a dead world literally the end of the world has happened spreading accross each and every continent infecting everyone it can, the man had a blessing in this ruined world, he was given the same game system he created and is immune to the infection but there are more secrets to the system then he knows and in this world where death is a never ending threat people learn who they truly are, so the question is who is he?