Raw WN link for this chapter:
https://ncode.syosetu.com/n6328ec/13/
I'm sad to see this manga marked as "completed", because the MC wasn't a stereotypical sociopath.
He actually felt somewhat normal, even if immature teenager. Which was in-role.
Yah, I think people claim "sociopath" way too easily when they see MCs killing people.
Sociopath MCs are actually rare....
That said, if anything he isn't normal.
He's too scared. Yes, it would work if he was a new high schooler.
But he's been fighting monsters and facing dangers and yet he's still as scared as a high schooler who has never had those experiences.
It's just sloppy writing. He should have some level of confidence and not be scared of everything.