I like the MC, he is cold but not the robotic cold that we see all the time. I also like the relationships he built with others, it fells natural and not something forced for the sake of the story.
All in all I generally like this manhwa.
Other then Reika being an annoying teenager that doesn't appreciate her parents, she is fine.
I don't blame her, she knows nothing and acts according to that fact. We all leave behind our parents back because they sometimes worry too much.