Kiyoung being shocked is valid tbh

The 1st timeline Kiyoung was someone who never had close connections and was filled with hate from the very beginning. He pretty much seeks out destruction of the world and so in process kills anyone he finds useless.

Although this timelines Kiyoung is an asshole at times, it's usually towards the ones he considers a threat against himself and his group, he's not actively hateful towards everyone new he meets. Also he's pretty set on being in power along with his group(that he is attached to in this current timeline) and on later chapters also we can see that he wants to make development too.

So yeah seeing himself be a complete psycho would be a shocking thing to him since he's originally not someone like that, he's not evil, he is an asshole and does acknowledge it himself but he's not evil.