Adding additional theories related to the special episode tellung bits about the story.
The book Kodoku legend. Pretty sure that this was the curse used to poison Mugo.
I only looked at wikipedia, but Kodoku is where a bunch of insects or snakes are placed in a jar and they fight to death there. The insects/creatures that are still alive were fed to the criminals, poisoning them. You can keep one of the remaining insects to get luck.
Past life Jaheon might be a scholar, and maybe studying ancient curses. And knows Kodoku, and the people might used his studies to kill Lee Muhan.
And also TIL Mugo is a curse. Search on google k-occult Mugo. I think Lee Muhan is a very important person who fell in love with the teacher/scholar.
I know that modern au extra (speciat episode) is kinda foreshadowy. i was wondering about the ages on that one, where the monster Mugo is the oldest from the siblings, and Jaheon being their teacher is the oldest.
Maybe the personality age in the modern AU is like monster Mugo being the oldest, because they meet when Mugo was young.
Then the middle one is the horny Mugo because definitely, Mugo was the first one who gets attracted to Jaheon, and as a young horny guy, was too pushy with his feelings.
And finally the Older Mugo will be the youngest out of the three because something happened that Mugo needs to be serious. My theory is Mugo might be a high official that needs to marry politically and might be coerced to act serious but deep inside, he is still attracted to Jaheon.









Not suprised. This guy fell in love when the puppy punched his face.
Way before. He fell in love at the casino.