I had a theory regarding what might happen after the ending of The Novel’s Extra, so if you haven't finished it yet, do not read. Spoiler: Regression So Chan Nyue found a stone that said it could make her regress to a parallel universe, and while it's safe to say that there are all sorts of potential disasters this could cause (even if Baal doesn't exist, maybe a new demon is created to take his place). But one interesting thing to think about, is that if she regressed in order to save her brother and get together with Kim Hajin, she probably wouldn't even meet Hajin. Hajin was an existence outside of her world, it's why many things such as spirit speech didn't work on him. The stone of regression could make a parallel universe, but would not have been able to copy Hajin, the author, who was unique existance outside of the worlds boundaries. So if she used the stone to regress, she would have only found Kim Chungdong and not Kim Hajin. Another thing that bothers me, is that when he first arrived in the world, he was supposed to be a nondescript extra with a blank question mark face (which makes no sense considering that every person in that world was completely real) but then kim Chungdong was revealed with a similar face. Did the co-author alter kim Chungdong's face to be similar to the author's? Was it left as a question mark because the co-author needed time to replicate the author's face? Was it just a joke harassment from the co-author? Also, in the end Hajin never used his privilege to ask a question to the co-author or recieve an item. Or was that part of his limbo experience? Also, i really wish that they used the interactions between Hajin and the people who know he is the author more for comedy. Like Jin Shinyuck badgering him with "why tf is Kim Suho that bastard the protagonist?! Why aren't I a drop dead gorgeous beauty??" ("I hadn't even decided your gender yet! Blame the co-author!")