Na-Kyum Baek is also known as 백나겸.
Na-Kyum Baek is male.

백나겸
Abandoned as a child, he was raised at the house of Ki-Saeng. A talented painter, he would come to paint erotic themed art under a pseudonym before leaving that to live as a drunk.
He feels all the nobles are only noble in appearance after getting to know Seung-Ho. Painting from memory, he ends up tearing his creation after considering it filthy.