Those 'NPC' are probably players like them too. Either they were already there before Doha's gang or they playing a different kind of game. Maybe it's a bit of a reach but at this point who actually knows where this story is headed. You know games have like different modes right? Aside from the main story, usually developers create mini games or smth like that to prevent the players from getting bored. Maybe those 'NPCs' are playing a different mode, so instead of trying to avoid/kill the killer, they've got to mission to kill other players instead.
My third theory is that like Bada, they're an anomaly. I mean, who thought that you can give an NPC a cassette to save their progress? That's probably where Seongchan got Bada's tape bc it wasn't explaimed. They just said they made him save his progress. We knew that a player can get two tapes (maybe even more because there are multiple maps). Those 'NPC' probably went to that storage, inserted a tape in the player out of curiousity and saved their progess accidentally. Now they don't know who's the killer and who isn't because they're not genuine players like Doha's gang.
THEORY TIME!
Those 'NPC' are probably players like them too. Either they were already there before Doha's gang or they playing a different kind of game. Maybe it's a bit of a reach but at this point who actually knows where this story is headed. You know games have like different modes right? Aside from the main story, usually developers create mini games or smth like that to prevent the players from getting bored. Maybe those 'NPCs' are playing a different mode, so instead of trying to avoid/kill the killer, they've got to mission to kill other players instead.
My third theory is that like Bada, they're an anomaly. I mean, who thought that you can give an NPC a cassette to save their progress? That's probably where Seongchan got Bada's tape bc it wasn't explaimed. They just said they made him save his progress. We knew that a player can get two tapes (maybe even more because there are multiple maps). Those 'NPC' probably went to that storage, inserted a tape in the player out of curiousity and saved their progess accidentally. Now they don't know who's the killer and who isn't because they're not genuine players like Doha's gang.