You worded this so clearly and eloquently and dissected it to the T. His words and actions are poetry sometimes but some readers are so blinded by hate that all they see is his head on a pike. I dig it.
i wish i could double upvote this topic
I think Seungho can be understood. I do understand him and his horrible actions. Yet it's really hard to like him or forgive him. His behavior overall is very consistent. Just like you said, if you deceive him, you will get hurt by him. As simple as that. He made tremendous efforts for the sake of Nakyum when he believed his feelings could be mutual, but as soon as he realized it wasn't true, he just stopped. I foresee a tragic end for him although I still think we will have a sweet romance between him and Nakyum before that. Maybe in season 3!
Seungho cannot be understood nor forgiven but even in the worst chapters the author manages to add Seungho betraying himself when he mistreats Nakyum.
The biggest offense one can have on Seungho apparently is to try to deceive him. The morning after Nakyum disappeared, we got a sequence of images that was Seungho remembering the sex he had with Nakyum the previous night and it was a passionate one. Even if Nakyum himself didn't voice his feelings, you see that Seungho took the sex between them as Nakyum being with him because he wanted. Come morning Seungho is deducting that all that was a lie and he was fooled. And being deceived is capital offense in Seungho's world,
He also vowed to not let his feelings or guard down again. However, Pay attention to this strange confession that only works for a character like Seungho:
"When I think of how you and that tramp tried to deceive me ...I want to tear her to shreads and shove her in a pigsty ... (this shows how hateful he is feeling, how horrible he is capable of being)
... But I will restrain myself a hundred times over since she is your sister. ( why? why Seungho the almighty heartless noble would restrain a hundred times over to do something because of Nakyum? )
The best part is that because his actions are so horrible, none of them realizes what he is saying with this.