Quote from T1
...You get some omake chapters with the young kings concubine. She plays a role in showing how the people sees the king, how he really is, and what happens to her cuz she's the kings concubine. She got another concubine as best friend.
You also get to see assassin coming after the king and you find out about the scarf perso who's been together with Shin after they met eachother in the first battle. You know the person who's Shin's right arm but still much better at fighting that Shin...
but they did actually use/shown this in the second season