PeachBlossomGoddess:
I think he should be and maybe we are just over complicating it and Kunwu is just Ling Han, as YHS obviously thinks he is.
The reason I think he could be someone outside of NBIS is there are already a ton of Japanese spies in NBIS. Why does Kunwu need to expose himself like that when he already has a bunch of moles stashed there? Also Kunwu seems to be following Milan around a lot. How does he have time to do that if he were stuck in some high post in NBIS where he has to be at meetings etc all the time?
Ling Han is on my top list and I am happy if he is Kunwu.
He is also the same height with Chengyi, like the poster, even if heights can be manipulated for a promotional poster.
Yes, he is the one YHS has been suspicious from the start, and he was always around, in Shanghai then Changsha.
Ling Han also has the people working for him, who probably the one who followed Milan around. We know 1 janitor, but he could have more working for him.