The faces of characters get clear when Dohun likes them or knows how they tick.
Hanseob and the father are still unpredictable, so you can’t see them clearly. That, or he understands them, but hates them. (The boys he killed were like that too.)
But in past chapters, the professors faces are clear, Seongmin, as well as the fat head manager.
And of course Yuwon, the love of his life.

is dohun asking director jin to k*ll someone? his 'father'? is he gonna ask director jin to m*ll him if his 'father' captures yuwon and k*lls him?
also, why is director jin the only person dohun can "see" except yuwon? can anyone tell me? if i remember correctly, director jin was faceless in the starting chapters, i forgot if he was faceless the last time he appeared or not.