beta
i reread the manhwa and found in ch 25 where kiyoon was being tormented by a ghost in the form of yuran it asked him if he was going to really delete the video of the ghost manager masturbating, which kiyoon did and the ghost (still in yuran's from) says that it "can't be careless anymore" followed by that kiyoon goes to the bathroom and sees his appearance in the mirror with RED EYES. then he wakes up again in the loop and tries to leave but the ghost manager catches him n he gets sa'd. when kiyoon passes out from exhaustion n the ghost managers waits for him to wake up he says "help me"
so my theory... the red eyed ghost may be the one that rang the doorbell in ch 16 and followed him inside (also might be the one that pushed him in ch 2). most of the time that entity is either taking form of yuran, jumin n other ppl but never the manager's....
also both ghosts have something in common which is hating on being compared to the manager, and are interested in kiyoon but just differently..