Global Cataclysm: I Built a Mechanical City

Global catastrophes, various disasters one after another, Falling meteorites, a tide of mutated beasts, global cooling, virus zombies... Betrayed by his beloved, Chen Xiaotian was reborn a few years before the disaster! The system is activated and the shelter can be upgraded infinitely! While others were desperately trying to survive, Chen Xiaotian accidentally built a mechanical city where he took baths and drank tea every day! Chen Xiaotian: "Wangcai, what do you think they are doing?" Wangcai: "Become the daddy of mutant beasts!" Chen Xiaotian: "Go catch those mutated beasts and roast them. I'll upgrade them for you!" The words fell. Wangcai is huge, one meter, three meters, six meters... Then, a little mutant beast appeared in one mouthful!