
He has issues cuz not everyone reacts or turns out that way. Regardless, I forgot but some has mentioned not only did he live thru his mom's depression and (alcoholism) but he loved I'm poverty cuz of that guy that t blackmailed her. Then she passed away, and while he was placed in an orphanage, once he was adopted his adoptive family was abusive and neglectful and treated him like dirt. Cha TaeKyung got pulled around by him a lot. So idk why he clung to him like a rag doll. But enough of that.
Still, nothing makes sense. (Given the spoilers I mean, the motives of the characters.)

He lived in poverty due to the blackmail. And is it because TaeKyung had finally found out who the murderer is but sided with them instead of HeeSoo that HeeSoo finally snapped?? I mean, the kid was INSANE already, but like....why did Cha TaeKyung abandoned him?!! Because the WHOLE PURPOSE THIS WHOLE TIME WAS JUST TO PROTECT HEESOO AND PROVIDE FOR HIM, SO THAT NOW THAT THE CAT'S OUT OF THE BAG HE DECIDED TO ABANDON HIM AND RETURN TO ADOPTIVE MOM INSTEAD?!?

I don't think it's gonna be like that
I mean the whole thing is about Heeseo being paranoid and stuff
So I think the reason would also be his paranoid ass thinking Mr. Cha's gonna leave him because he's not good enough or something like that
Also I can't imagine Mr. Cha siding with anyone other than his beloved teacher
Idk this story is so interesting
What hurts me the most is that the psycho himself seems to be trying to get better but he gets lured in by others ╥﹏╥
I'm not trying to justify this peace of shit's actions
I'm just wondering if it was possible to avoid what we saw in the first chapter if others didn't keep butting in
We all know that these behaviours are most likely to get worse when others try to "help" without caution