Bruh, there were 2 cocoons on that roof. Where is Hyuk, a?

Yeah. I was just expecting hyuk will awake too. And be with his sister. We can swe that after hyun came back, hyuk's sister is really sad and maybe wishing her brother will come back too

So there's 2 posibilties imo, and it's up to reader to decide what they think
1- he shows up eventually by somehow regaining emotions and memories like hyun did.
2- he wanders aimlessly after not regaining any emotions or memories, and becomes the "perfect" human, which was the end goal.

And it's hard to determine bc Hyun was just built different from the beginning lol. And he had the music to help him too. But it's nice to think Hyuk also regained his consciousness

I also hope he will regain his memories and emotions.

Hyun might have not got his emotions back. The only reason I think hyuk got his emotions is because he listened to that song, which made him feel again