Guan Fei has no idea what happened to the world. One moment everything was fine, and the next, the apocalypse had arrived. How did life end up like this?
Since he's here, he makes the best of it. He can only go with the flow, heading wherever he can find a bite to eat. But if you think Guan Fei is an easy mark and try to bully him, he won't go easy on you.
If he had to put up with things before the apocalypse, and still has to put up with them after it, then what was the point of the apocalypse?
Somehow, before he knows it, he ends up becoming humanity's hope.