I read it on webtoon in early to mid 2019 I forgot the title(also I'm not really sure if it's a bl, that's the only thing I remember)... the story was like set in the underworld or something (but it was like in ancient china or korea yk with those red castles and pavilions) sinners were being punished and there were many rulers and like one of the rulers is incharge of the men because he was homosexual (that was the term used) and also only one sinner caught his attention because that person was really stubborn, and like he was put into many test (if I remembered it right) the ruler and the sinner had a love-hate relationship, also there were like skeleton rulers, i think the genre was fantasy and horror