You seem to not understand, he’s clearly manic, the whole point is everything he’s doing is “creepy and weird”, he’s actively spiralling. He was clinging to a singular person and his mental state relies on this delusion he has, the delusion gets shattered which, sends him into a deep pit of depression, it only makes sense his mind will turn to suicidal thoughts. It’s not “neglecting his past”, just because his childhood was traumatic and lead to his mind deteriorating, doesn’t necessarily mean that was his cataclysm. His mind is now fragile, him solely relying on one persons existence was bound to end in him mentally declining. I think you have quite a shallow understanding of mental health, no offence, it doesn’t take a huge traumatic event to to drive someone over the edge, sometimes it’s the “small” things that have a larger impact on a persons mentality. I’m sorry if this is worded rudely, your comment is a little insensitive so I hope you look more into these themes if you want better understanding.
What I meant was that the author hasn't given enough context to understand the characters behaviour and that's just make him look creepy. And by "neglecting his past" I meant his past trauma may have made him this attached to a person to do such things, I just think the story should have shown more of the past that created that fragile mental state. we both don't know what caused him to be like this. What I'm saying is just my pov and opinion I'm not claiming anything. The author hasn't shown us that much to jump on conclusions like the character is naturally a Maniac.
Tbh his behaviour is kinda creepy and weird. Author should have shown him being suicidal is not only his relationship with ml but also his past. His past should've been more in spotlight till now I think. It just kinda looks cheap when someone decides to suicide over a situation like this. I mean all the reasons for his suicide shown is his relationship. It's like neglecting his past. Idk i just feel like this