I don't think it was particularly subtle, but this girl definitely has some connection to the girl who is related to Rapunzel and looks very similar to her. I don't know if she's that dark fantasy version of Cinderella, but who knows?
Anyway, given the story's previous events, I'm surprised the manga's global political lore doesn't feel like a mix between Berserk and Game of Thrones. However, it's possible that as the story progresses, we'll learn more dark things. Also, it was quite interesting to see Rapunzel openly admit that Mikel's current state scares her, even though she still loves him. Judging by how Aka is delaying further exploration of this very situation, I'm even wondering what potential cliffhanger about Mikel's condition awaits us in the next chapters.