Responses
totally, Arima is perceived as this emotionless badass killing machine terminator type for him to just kill himself theirs gotta be some kind of a reason behind it no matter how small.
He's displayed as such because no one can really get close to him. He doesn't say it out loud, but I think Ken was probably the closest thing he held to him (Arima).
better make the next chapter explain why arima did it. Is he just tired of his life or he cannot kill ken for reason I cannot clearly understand.