Bum is going to commit suicide to free him from his pain.

I hope not but who knows at this point lol If anything, I see Sangwoo trying to commit suicide to put his own mind at ease finally. The man is competely out of his mind, hallucinating left and right with random flashbacks of his traumatic past. I can see him cracking under pressure soon. Bum already tried to take his life once so idk if Koogie would make him do it again.

If Bum ends up doing it first though, I still think Sangwoo would follow right after out of guilt or something.