Responses
(Warning: some contain dark themes/images)
Royal Servant
Blood Bank
Dark Heaven
Sign
Black Mirror
Heaven & Hell Roman Company
A Painter Behind the Curtain
(You can find a bunch more by going to the Yaoi tab at the top of the home page, selecting "Webtoons", then unselecting the "ongoing" tab, and clicking the "OK,GO" button. That'll just give you the stuff that's completed)
Completed bl Manhwas please