Well, usually I am not a comic person, but since thus series provides additional stories taking place after the TV series' episodes and the only format available was comics, I had to go for it.

The promise takes place just after the TV series and it's about the restoration of the four nations after the defeat of the fire lord. Again, we see a very insecure Zuko in front of difficulties, always under the negative influence of her sister, Azula. That's Zuko, the same as in the series. Themes like integration and diversity are dealt with in this volume.
I enjoyed a lot staying in the avatar world a bit longer and see how the world is going to change.