I think he has ADHD, daddy issues and rich kid with too much muscle for brain syndrome, with closet gayness going along with it. He is so freaking insecure about himself, but is too proud to be vulnerable and open to Jun about any of that
Spoiler : he's not in closet and pretending to be insecure about himself but he does have insecurity about jun liking junwoo and under impression that there's no way jun ever likes him back
Spoiler
He is out with his family, but he isn't openly gay before his peers, he did react quite hostile when people were calling him that if I remember correctly
Yohan pls... shut up oh my god bruh switch up the century im fully convinced hes bipolar or SOMEWHERE on a mental illness spectrum im so