I know this is not possible. Instead, the author must have set up a stylistic rifle on the mantel in a 2006 book, based on story elements going back to her earliest stories, and then let it percolate in our subconsciouses for six years before giving us a (partial) explanation.
This is playing the game at a very high level. Smith is not the only author doing it these days, but GRRMartin and Steven Erikson and even Pat Rothfuss are Big Names in Fantasy. I say that Smith needs some attention in this regard. Norsunder deserves credit as one of the great Dark Powers in modern fantasy, a boogeyman whom nobody knows what they want. They just pop up occasionally (all ancient history, of course, doesn't happen these days) and instigate some trouble or make some people disappear. And by "they" I mean this ordinary-looking guy, who isn't scary until you read some history and realize he was mentioned two thousand years ago. And he isn't even one of the important ones. I'm not conveying this very well. It's really good setup.
Banner takes place about four centuries after the Inda books, in Colend, the other side of the continent from Marloven Hesea. The tone couldn't be more opposed: the Colend court is mannered and leisurely to a Guy-Gavriel-Kayan degree. However, the Marloven empire is still lurking, military as ever -- though not in the same way as Inda's nation. (Another lurking theme is how the history of Marloven Hesea is the history of the Marloven military academy. This is never stated, but after N books it's absolutely clear.)
The viewpoint is Emras, a young scribe. Scribes are rigorously trained to be honest and apolitical; naturally, Emras winds up ass-deep in politics and lies. The frame text (still not quoting) makes it clear that this ends badly; the book is about how. As with the Inda series, there are princes, princesses, wars, betrayals, and epic tragic romances -- although Emras is mostly an observer of the latter. Unlike with the Inda series, this book gives us some meta about the Inda series: one of Emras's jobs is to translate the four-hundred-year-old memoirs that (presumably) become the quadrilogy. (There are several versions, not necessarily all reliable.) And then the head-jumping comes into it... As I say, meta. And intriguing.