
Because Bada is a game npc, meaning he's a variable that should only exist in the game but instead he "gained" consciousness like a robot being "sentient". Aside from that, Bada also showed exceptional skills when solving puzzles and clues like what Seongchan and Doha observed in their first gameplays. They stated that they're really bad at the game that one puzzle would take them 20 tries (I think brown hair guy mentioned this)
The browned-hair guy also revealed that there's a possibility of escaping WITH an NPC so it's possible that Doha and Bada will escape the game together. Makes you even more curious because if Doha successfully escapes with Bada, he brought a game NPC into real life.

Yeah but how did they figure out he’s an NPC if the tape affects him just like everyone else? Is it just because he had to be persuaded to get in the car?
If u’re referring about Seongchan, i think he might have just lied about NPC being able to escape the game so the others would feel less bad about using Bada to finish the puzzles. Nobody has escaped the game, so how would they know whether NPCs can escape or not? (Of course i am also rooting for Bada to escape. Otherwise Doha can live in the game forever, that’s fine too since he can literally just kill the killer everytime uwu)
I’m confused.. since the players turn into an NPC when their tape is stopped and regain their memory after its played again, how is this any different from Bada? Like aside from spawning in the car instead of the tunnel and not being able to kill the Killer, how is Bada different from any of the other players??