Though why did they never bother to check the identity of the killer scooby-doo style? Wha...

I think Bada kind of did? In the earlier chapters he describes the killer as a force that couldn't be messed with because if you kill the killer he would just respawn, so I think that makes the killer like the items in the game? So identity doesn't even matter if it even has one

The thing is I'm not sure if I could trust bada cause he's like an unreliable narrator at this point of the story,,, also idk what he meant with respawn like does his wounds heal and does he get up or does he reappear somewhere else after they try to escape?

Hmm I reread the story and yes Bada is a unreliable narrator but I found out 1) when Bada tried to kill the killer he always came back to life 2) Doha killed the killer in the hidden room but there was another killer in the forest some panels later that killed the almost couple and later Bada

Also its unlikely that the killer is one of them, he tagged along with all of the characters in previous rounds and every last one of them dies somehow.

I just thing the killer is part of the game setup that cannot be permanently removed in a round, so he does not need an identity that's just my theory tho maybe later on we will get more info that rebukes this it's only been 8 chapters afterall

If I remember correctly, he did mention something along the line of him being unable to take the sack off.