10 dramas where the villain's motivations are explained towards the end and their motivations are understandable and learning about them makes the villain more multi-dimensional..
10 titles where the vvillai's motivation is explained for the watchers to relate to them but it didn't work on you or the motivation is still not relatable for you (like a redemption arc but for you the villain was not redeemed.)
1. Surgeons (2017) - I can't understand why the 'villain' decided to hide the dead victim's allergy to anesthesia agent/medicine and put the blame of malpractice on ML's mother just to make sure the new medicine get approved asap. Saying that he's not in the wrong multiple times after confessing (which meant he indeed felt guilty over ML's mom getting jailed and died in jail iirc). And then he gave a mouth-to-mouth resuscitation to a plague victim and died of plague. What did the scriptwriter trying to prove? But it's a good drama with good casts.
Give me a bit to think of all the CDramas that works for this categories; not sure the bad guys are villains the usual sense, just nasty pieces of work.
4. Black Knight: The Man Who Guards Me - Antagonist Sharon / Choi Seo Rin is such a piece of work. And there are neverending explanations of how she got to be that way. Her work here made me a lifelong admirer of actress Seo Ji Hye, because she was so good and making me hate Sharon. It took me a year to watch the final two episodes, I was that activated.