yo, theory:
Eunyung seems to border the typical psychopath, but if he has a darker reason for it, than he's a really extreme sociopath.
Just to name a few examples:
- shows criminal behavior through stealing Haejoon's wallet
- a lack of empathy for others (the case with him "feeling" bad for Haejoon could possibly be projection of his own life?)
- a lack of remorse (doesn't apologize for his rude behavior)
- friends are of convenience
And Haejoon seems to be a less extreme case of sociopath, but still none the less.
Just to name a few:
- over aggressive behavior
- socially out-casted and anti social behavior
- mentally abusive mother (idc what you think, its psychologically damaging to force your religious beliefs on a child who clearly gets distraught by it) and background of victimization (the bullied kind, not the playing victim kind)
I dont know if Eunyung (tent guy) has an actually traumatic background but just to be clear,
"Lack of empathy" does not mean "Lack of sympathy"
If you cant feel another person's pain if you've never experienced what ever pained them yourself, its a lack of empathy.
Euyung probably sympathized, placing himself into Haejoon's shoes that other chapter. Maybe for a brief moment. But yeah, that's my theory