Nice comeback for the series. Yangchen was done dirty sorry. This goes back to the style of the first two Kioshi books. While reading it I rewatched the original series episode that features Roku. Some small things were changed, but for the benefit. 
The action was well paced and interesting enough. Though the tendency still seems to be to have some cheesy moments. Very YA, which I am not that much a fan of. But it did balance it well with some more serious scheming setup, that I am looking forward to reading the pay off for in the the next installment of the series.