Came back to re read this, and I used to ship them, and still do.
At the end of the day, both of them were horrible people, and they deserved to be punished, but not in the way they were. A mental facility would have been best.
Songwoo, for starters. He went through a lot, and at such a young age. He was delt a horrible hand, and had no way to cope with it. He then began venting these bottled emotions onto random people and murdering them(not that I condone this, just that he could have been helped) then, bum showed up, he abused bum, he raped bum, and tortured him, but does everyone forget how bum changed him? He became better, all he needed was one extra push into therapy, and he could have lived a normal life and understood the issues with his and his abusers behaviors. However, his paranoia got the best of him. This is why I feel bad for him, he had his hope, but his mental health got the best of him and led him down the road to insanity and inevitably his death.
Bum on the other hand, while he was a stalker, stalking is not in any way a reasonable cause for the abuse sungwoo put him through. And this clearly fucled his mind up, leading to him murdering and also lowkey going insane. He had a horrible childhood similarly, but his stalker mindset was his downfall
However I do believe they both really loved eachother, and made eachother better. I just wish they could have had a normal healthy relationship with communication and understanding in eachother. This story is really tragic, and I wish some people could understand that this is what a lot of people are going through. It never makes it okay to murder or harm another, but some people really just need help before they reach that point where they become a danger to themselves or others.