The question that remaining unanswered
What happened between the first and last frame?
Seriously, what? When I think about this, I have several ideas as the events of the first frame could develop and this does not lead to the third frame. Suppose Zuko and Katara remained to stand. What next? And then the whole army in the capital is running to find out what is happening at all? Why do fiery explosions rise over the palace during the coronation of the heiress of the throne? Where did all the people leave the palace? Is the heiress of Phoenix King safe? And all! Zuko and Katara is the two against the whole army. They either go to prison, or die or run away with the help of Appa. They can even try to take Azula as a hostage with them on Appa. But this is very unlikely for them. And no of these options leaves space for the ending from the third frame. What else? Will they pose in the palace with Azula hostage and wait for the palace to storm? Aang will learn teleport and save the situation? But even this option does not lead to the third frame! So what happened at all? Neither in comics, nor in novels, there are no answers anywhere.
Just a plot black hole.
And yes, the warriors of Fire Nation standing in some rows with the warriors of the Earth Kingdom and the Water Tribes after a couple of weeks (months?) after the centenary war, this is too lazy …