This is brilliant. Done with an ink pen and...I guess he dry brushed the colour onto it after that. Calls himself 「縛(ふぅ)」 on pixiv....so what shall we call him? I'm just going to use bakufu for the moment, but other suggestions are more than welcome.
They're indicating their name is 縛 and they read it as Fuu, for some reason. I'd use fuu_(artist), only we already have one. Their pixiv URL is futian.