That's what I think..
Kyungsoo crys for Yule cause deep down he is still in love with him or at least Yule is still an irreplaceable person to him.
Kyungsoo crys for Dong-hyuk as he thinks it's his fault to turn Dong-hyuk into this kind of person. Dong-hyuk was a sweet and kind boy before but his emotion has become very unstable since Kyungsoo come back. It's obvious that his personality is twisting, just by seeing him threatening Yule with Kyungsoo's life can tell.
And finally why Yule keeps hurting Kyungsoo? The reason is simple: He indeed is a psychopath. And it's the way he shows his love that normal ppl like us will never understand :)
I do read Killing Stalking actually.. But I understand that.. Obviously I was angry with Sangwoo for treating Bum like shit but.. Some how this one is more twisted to me.. The way Yule used his brother n frnds to rape kyung.. That was the end deal for me. Idk how I kept reading it after skipping so many times. Why did I read it! It's f#king with my mind still!
I have read a fair share of twisted stories but this one beats all of those.
I don't get it.. What's Kyung actually thinking? He was crying for dong-hyuk then he was crying for Yuel too! It's so weird! Did I miss something?
Yuel is beyond twisted..he loved kyung I get it..but he never thought about kyung's feelings even once! May be he will be admitted in a mental asylum..