i have no clues and no solid theories, but its fun to read yours here :D
the only thing i suspect for now, is that both the ML and FL are seemingly too nice, for people who supposed to grew up in such harsh environments, one who has been shunned on being suspected not being really of bloodline, and the other, hell she is supposed to be an assassin!
they are both seem too kind, sheltered, naive at times, and not cruel enough. meaning, if this would be like Game of Thrones, they would be the ones who will kill everyone else at the end, and then kill each other.
alas , since this is c-drama? haha the suspense, the not knowing is way too cool.
anyway, since i am not emotionally invested in anyone, an ending, like the red wedding (all ends in an bloodbath) would be fantastic! or both groups, Gong and Wufeng, all but annihilated each other, only to see that a third party came out, and admit they were all played.
(oh, and elder sister is still my main suspect. she is female, she has never had any chance being the sword wielder, therefore she must hate and despise everyone else , deeply. If i were her, i would betray my entire clan and family, and let them all be killed, moral and ethics be damned. )
however , there is more mystery added in fifth eps. coz this strange "heat thing"? its midnight here, so i am too tired to rewatch that ep from today, but maybe more is coming tomorrow.!
goodnight!