A man

I see now...not just some random plot hole

I think in some chapter where the curse first came up they said that they are not allowed to say the name and additionally she also looks like a boy to them. Idk if im right since i‘ve read it somewhere, can be also another manhwa but im pretty sure it was this

I commented before I got to the chapter where it was explained lmao. It was indeed this one (▰˘◡˘▰)