God Rewards Hard Work, Starting from Refining Medicine and Breaking Through the Wasteland

A cataclysm turned the world into a wasteland. The people who survived built barriers one after another to survive. When he woke up, Fan Xiao traveled beyond the barrier. Outside of civilization, order is out of balance and human life is worth less than grass. Fan Xiao takes Tiandao Huoqin with him through time, and he can always be invincible as long as he goes down. So the question is, in this wasteland where life is a problem, where can I find skill upgrades? Fortunately, apart from the system, Fan Xiao's supernatural talents are not bad either. It doesn't allow me to level up safely, so I have to fight my way through the wasteland first.