oh wow, I understand now. Thank you for confirming.
Can you also confirm the accuracy of translation in chapter 34 when Sh said "무서워서 네게 감히 뭘 할 수 있겠느냐?" It's translated as "I cannot do much with you at this rate, can I?". It's just bugging me a lot because I use google translate and there were the words "scared" and "dare", but those words weren't included in the translation and that's why I was skeptical at the accuracy of the official translation in the first place. Thank you.
I'm not trying to say Sh doesn't. But we can't deny the fact that he is the reason and the person who makes Nk suffers. That's why I said I hope his mental illness can be treated soon. I know Sh suffer in the past too, and it explains/is the cause of his unstable personality/mental illness/ lack of remorse. But it doesn't justify the suffering he causes for Nk, doesn't make his wrongdoings right or acceptable. I feel for him, but right now I feel for Nk more, bc he's the victim you know. Until Sh's backstory is revealed, i would only side with Nk, because he's the innocent one.
I don't think author portrays Seungho as someone with mental illness. He is more properly described as someone who is an eccentric, (surprisingly) obsessive, and... he's just being a Lord with special status. Reason why he's so full of himself and (ridiculously) demanding most of the times.
These were common traits of ancient Korean rulers, but not necessarily a mental illness. Maybe what he does is extreme for modern people (us, readers, common people), but that's just how these Lords roll in the past.
In my opinion, the author did a great job on her research, the background, characters, personalities and timeline as they are drawn and portrayed as realistic as it should be.
If you really believe the translator is deliberately translating the series incorrectly to make the story look worse then contact the author directly. Go on twitter, tell her you buy both the raws and the translation but you have to rely on a friend who's still learning Korean to translate it for you and she says he refers to the teacher not the painter in that scene. Ask for clarification, that usually works.

I bought the official chapter too and it is totally different!
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He wasn't going to kill the teacher, he was going to kill the painter, which really makes less sense to me!