Something
hollyxu commented on yesterday - that at the start of the story but Guo Jing and Yang Kang are blank slates who later get shaped by circumstances, made me think.
If you think about it, at the start, YK and GJ are in about as equal a position as two people not sharing DNA can be - they are each a son of a Song hero and his loyal wife. But from then, the paths diverge even before they are born. Guo Jing is raised as a nomad in the plains of Mongolia by his loving stern mother and 6 freaky teachers. He is told from birth about his Song heritage, taught the whole "Songs are the bestest, Jin are evil" mantra, and knows his duty upon growing up is to find the man who killed his father and take revenge, and also to find his 'younger bro' Yang Kang. When he goes to China as a grown-up, he can follow the clear goals set for him - all that he needs to do is straightforward and he accomplishes it without much fuss - find Daddy's sworn brother? Check. Find Yang Kang? Check. Take revenge? Check. Become awesome Song hero able to fight evil Jin? Check. There is nothing in this agenda to make even a more complex man than Guo Jing happens to be to doubt the things he was taught or confront ambiguities.
Now take Yang Kang. YK gets brought up as the only loved son of a Jin prince. He has no idea the man (who is an excellent father to him) is not his father, he has no idea about any revenge or heritage, and he's certainly not been taught the whole "Jin are eeeeeeevil, Songs rock" mantra of the Songs (I doubt he's even ever seen a Song except for some guy about to be executed). What he's been taught his life path is becoming a Jin ruler after his idolized father croaks, hopefully many years in the future. By his very upbringing, he is someone who cannot accept the automatic credo that being Song is the best and Jins are evil - he knows they are not, not any more than Songs are. When he gets told the truth about his heritage on his 18th bday - this is a huge revelation which turns his whole world upside down (his mother totally fails - she should have either kept the secret to the grave or prepped him). He is basically told he belongs to the people he'd beeen taught to hate, that people he regards as his own are his hereditary enemies, that his father is someone he's never heard of before, and the man he has to take revenge on is the man who brought him up with love. He has no easy path. He basically has to confront everything in his life being a lie (hello, trust issues!), and he has no comfort of ideals and certainties because for him they are not automatically either - revenge is not clear-cut and neither is who is good or evil. For him to accept his 'duties' isn't as simple as it is for GJ who can fulfill his quest and come back for Mongolia. For YK to accept it means giving up all his past, declaring enmity on everything he's believed in. And then there is the fact that as a royal he is simply not equipped to be a poor wanderer - he simply has no idea how - he takes comfort and money and being obeyed for granted.
The thing that is so heartbreaking about YK's story is that he tries - he walks out on his Jin father (even if he cannot bring himself to wreak vengeance on him), after a bit of teen rebellion he accepts his Song identity and also manages to shelve his pride about work and alms and things like that - if left alone, he'd be very functional even with that baggage. But fate does not allow him to keep at it, to have a clear-cut path - he can never have any certainty. He has to go back to the Jin (as a sort of double agent) as the only viable option to survive and that is a far cry from clean and simple vengeance. He has to confront the fact that the whole Song/Jin dichotomy is not simple, the way GJ views it. After all, it was the Song officials who hunted and tortured him and Nianci, it was a Song peasant who betrayed them. But he can't go back to the "OK, then I'll be a Jin, they are awesome" world either - that would be a betrayal of his birth parents and also his complex love/hate relationship with his adopted parent won't allow it (the man killed his bio parents, and hunted him, and YK knows that him being taken back is part of Stepdaddy's screwed up revenge plan, so he is not truly welcome back - it's all headgames and he has to be better at them then stepdaddy to survive). YK is, understandably, basically one step away from just viewing everyone in the world as awful and lashing out at them.
Anyway, no idea if this ramble is going anywhere, but I found it fun to ponder.