Awesome actually, im exited to see where this next arc takes us. Thanks for the TL!
I am calling it now, this "Maiden of the Skies" gets possessed by Lilith permanently. Why?
1) Lilith sounds like Kangwoo's greatest demon ally and would be worth bringing into reality.
2) His refusing her clinginess when she looks like Cthulu's offspring makes sense, turn her into a pretty human makes it harder for him to resist but he now has a love interest (Seolah) so still has conflict
3) She (the Japanese girl) sounds like a character they'd want to keep using, and would need an excuse to get her to Korea.
4) We just saw what demon-possessing looks like and this girl's power is also possession
5) Her character design is that of a Miko so she is likely to be a very reserved character architype which will be funny when she is possessed by the literal queen of succubi.
I do find it interesting that the authors have started printing more love rivals, but I suspect at least this one (Lilith) was planned for a while, unlike random-daughter-of-chinese-old-master.