The MC is a sociopath and his sidekick is practically a saint - I really hope this goes a deuteragonist route with Kim. Stories with asshole MCs can get grating with just the MC to watch, and so far I really dig the dynamic between Kang and Kim. They've both clearly got each other's backs first and foremost.
Kim seems like a pretty unique kind of character for this genre (he's too close, too consistently to the MC for me to think of him as pure comedic relief - the two really do feel like friends) and I like him a lot. Hopefully he doesn't end up sidelined.