I'm currently watching Dear Hongrang and I really enjoy the atmosphere in it. I would love to find more dark, historical mysteries/thrillers/dramas with little to no humor, especially slapstick. Any recommendations? 

I second 'My Journey to You'. There's also 'Fangs of Fortune' but that one is fantasy with demons and all.

 Hallaxa:

I'm currently watching Dear Hongrang and I really enjoy the atmosphere in it. I would love to find more dark, historical mysteries/thrillers/dramas with little to no humor, especially slapstick. Any recommendations? 

If you don't mind movies, I can't recommend Shadows in the Palace highly enough