
I was right from the beginning that there was a 4th one. Maybe the 4th disguised himself as the god mugo and carried jaheon when he was a child that's why jaheon felt a connection with him and keep looking for god mugo when he started living in the mansion. The 4th could be with a kind personality and the god mujo is a jerk one disguised as a kind one (based on his interactions with default lord mugo).
What a comedy it is. I was laughing every chapter