Doomsday Super System

The end of the world is coming, terror covers the whole world, and the earth becomes a hunting ground for zombies and mutants. Zhao Tianlei accidentally obtained a mysterious super system. Although he is not a saint, but seeing the tragic situation in the world and the death of his classmates, how can he stand by and look at how Zhao Tianlei, who has a super upgrade and exchange system, leads humans Fight against corpses, restore human civilization?