The obvious traitor was obvious, but this might be one of the shortest horror survival manga ever, so points for getting right to the gore rather than dragging it all out.
If this ever gets animated, it could be an OVA, at the very least.
Kind of get the feeling her motives is shes getting revenge for those who died and wants this guy to kill her as redemption. Also realized all the punishments are for those who attempt to save there own skin think she ended up killing last dude just because he had no issue to kill in Hope's of saving himself.
This MC takes stupidity to another level. His friend's reasoning was bulletproof. I mean, if the device was on him, then why did he need to take the her clothes off to get the device? to fake a scene in case MC arrived. Why not just use the axe to kill her and friend right away?