I don't think that yeonsang is actually alive or at the door because:
1. The ghost said multiple time that he ate him. And the legend says that the entity mimics a person/sound to lure their victims and then eat them. Applying this to the story now, it would be likely that bwom ate yeonsang and mimic him to lure other people so he can eat them, just like how he states that he was gonna eat gwompil in the first part.
2. if it is really yeonsang, why would he ring the doorbell ro his own house? why call out for geonpil when he can just enter his own passcode? Beom also did that when he first arrive and geonpil had also questioned why he didn't just enter the code when it's his house. so I think that this is another entity pretending to be yeonsang. or maybe it's his spirit coming for revenge?
I don't think that yeonsang is actually alive or at the door because:
1. The ghost said multiple time that he ate him. And the legend says that the entity mimics a person/sound to lure their victims and then eat them. Applying this to the story now, it would be likely that bwom ate yeonsang and mimic him to lure other people so he can eat them, just like how he states that he was gonna eat gwompil in the first part.
2. if it is really yeonsang, why would he ring the doorbell ro his own house? why call out for geonpil when he can just enter his own passcode? Beom also did that when he first arrive and geonpil had also questioned why he didn't just enter the code when it's his house. so I think that this is another entity pretending to be yeonsang. or maybe it's his spirit coming for revenge?