I think the rest of the people in the empire do have wings, they just aren't allowed to openly wear them (the king and duke are excluded from this ofc). It's explained briefly in chap 18
they all have wings (all black & white) but the only people allowed to openly have them are the king (sehyun) and the grand duke (nel?) since they both have the highest authority in the kingdom.
They all have Wings actually it got said in the early chapter but since the grand duke and The king is the highest authority in the kingdom so maybe they are the only one that is allowed to show their wings as a prof of their blood lines it got explain clearly in the chapter 18
ok i probably didnt read it clearly but i don't reread again, can someone explain why only Grand Duke and King have wings? wHat about the other ppl/citizen of their empire, do they have wings too but they dont show it on public? And if they have, their wings also black and white? did they all go through the pain of changing?