honestly the part upto beating the demon was fine, there were power spam parts but there were genuinely interesting and martial arts parts too or rather that's what most of them were, and the emotional conflict behind the power spam was good enough, and the assassin old men were wonderful
one disciple being decent was great too but the way mc's want for revenge manifested and his eventual reluctance, all felt written very out of character and somehow stretched out because of it,
and i'm fine with the others being alive, but the foreshadowing wasn't good enough, neither was there any reasoning or added possibility behind it all in any sense, it felt sloppy and totally out of place, only as a last minute effort to stretch the story.