I'm on ep. 29 and i'm guessing the hidden grandmaster is shadow because he's been a grandmaster all along but just pretending. Or the grandmaster is pretending to be shadow.
Even though the story is still interesting, so far this season isn't as good as the first. Not many big things or actions have happened. The only big obvious thing we know so far is that the emperor is very much on Fan Xian's side.
1. younger than second, older than 3rd.2. elder princess (emperor's sister)
It's not rank I'm talking about. Age determines who is first second or third prince etc. I'm talking about that. On ranking I know crown prince is first and he's the third prince, future emperor.