Era of Cataclysm: I Build the Strongest Fortress of Doomsday

A global natural disaster breaks out and civilization collapses. The protagonist Zhang Zhong obtains the "Calamity Lord System" and builds the first shelter. The world has undergone major changes, with extreme weather, virus outbreaks, insect attacks, and the collapse of human order. Zhang Zhong was originally an ordinary person. He accidentally awakened the "Calamity Lord System" and obtained a novice shelter.