It's been a long time since I saw TVB's LOCH1982 and was swept up recently by the adaptations in the 2000s - I thought the MNC most true to the novel is Shui Ling (LOCH2003) character-wise and looks-wise, but also liked Cecilia Liu's (LOCH2008) looks very much, but her MNC character is totally off from the original. Also been a long time since I read the novel, but the impression I always got was that he was taken in by her at the Joust For A Spouse. If he wasn't interested in her, he would have just left it as it is after humiliating her in public. But later made excuses to see her again by arresting her and Yang Tiexin (what a bad-a** way to woo a woman). Anyway, he was a total villain in the novel - LOCH1982's YK is unlike the novel. You should go to Wuxia Fiction in this forum to find out more.
Yeung Pan Pan is actually trained in real martial arts with the ability to display authentic kungfu moves, that's why I always thought Mu Wanqing (a top female wulin fighter) in TLBB was the role that suited her most, although MNC is what made her famous. However, as a character, MNC is known to be a weak fighter and rather easily duped delicate beauty type.
Here's Yeung Pan Pan kicking real-a**. She does all her own stunts: