Who Stole My Identity

That year, a perverted serial murderer was sentenced to death. From then on, Wang Yan became an orphan inexplicably. Another year, Wang Yan seemed to have turned into a monster. He was knocked back more than ten meters and could still move freely. When he comes somewhere to look for someone's footprints... "Wait!" "Something's wrong!" "The man who just walked by seems to have no head!" Is this still the familiar world before? Why is it exactly the same but weird everywhere?