I think he passed out , because he hit himself some times in the head, before killing the guy, i think....
good observation
Well he is also either some tough ass being cause they were all like he is very important for humanity wtf???
He said he gets weak everytime something happens in the town. I think its maybe when someone challenges his rules, his powers become weaker. Maybe the rules are set in place so that he has the power to protect everyone. That could be why the town's people all rushed to take care of him and emphasize that his rules are important.
So Guwon is a Frankenstein character. From the beginning, he just comes into existence and finds himself in that town. He likes so many basic qualities that humans have, which really shows that he was just created with a purpose. He recounts that he just felt like he had a strong desire to protect this town. And with him fainting in the last chapter, I have a feeling that the throw up after the kiss is like a response to him getting human emotions, like his very body are rejecting these emotions that he is supposed to be incapable of feeling? At least, that makes the most sense to me as of now.
What definitely doesn't make sense is the doctor's story, unless its bad writing, people in zombie shows don't just go with the guy who killed his family. The walking dead has shown me a thing or two lol, but its very odd, and I have a feeling no one in this town are in the right, especially with this setting where everyone is morally ambiguous due to circumstances.