When I finish reading the novel she was never mentioned anymore.
The one from the Radir clan? She's alive and back presumably with her tribe. Since Jinwoo got rid of the other demon clans, her clan is the only one left. She won't reappear in the story I think... if memory serves me right.
Good question! My friend and I actuay had a discussion about this so...
Spoiler
, so the girl in the demon clan during Jinwoo's journey in the 100 story building, her name was Esil. On that place, as was explained here in the manwha and the novel during the King's awakening with the dark heart that, were already dead. That would explain why Jinwoo, on that time cannot extract souls on that place since the one he is fighting with are dead. So basically the answer to your question is, no. She's already dead. She was only projected as a character inorder for Jinwoo to awaken.
i just wanted to ask if the girl w/ horns from the demon clan is still alive??? or will she live???