The End of the World: Bone-Eroding Winter

The first stage: The "Bil Fever" virus (codenamed "Black Frost") breaks out globally, with high contagiousness and high fatality rate (>70%). The difficulty in handling corpses leads to rampant plague and the collapse of social order. The second stage: Following the virus, a global extreme climate disaster - "Eternal Winter": Unknown reasons lead to a sharp decrease in sunshine and a sudden drop in temperature, accompanied by secondary disasters such as strong radiation dust storms, acid rain, and earthquakes. Freeze, darkness, and radiation become major threats.