![](https://pic1.mangapicgallery.com/r/avatar/66/u528541_50x50.jpg?2)
So basically my theory is : Seong ah was a boy that got kidnapped and eventually died. Whether the kidnappers killed and got rid of him before they eventually crashed and died is yet to be known but seong ah did end up dying.
His soul was eventually caught by the devil guys and was then used to make a Doppelganger. The doppelganger ended up looking like the idol (who we now know was seong ah's sister) because the devil that made him was daydream about her while working on the body he was to possess.
What a coincidence. Also if I'm not mistaken it's kinda crazy how seong ah is his actual name when he was only called that cuz he looked like the idol. I guess she used his name as her stage name? Am I tripping??
They're gonna break my baby jo heart aren't they??