I changed the title of this thread to make it more to do with the topic presented.
Zuko’s portrayal in The Promise has been the most controversial topic about The Promise. Here are my 3 main points about why I personally have no problem with it.
-Lets remember that we have only seen less than 40 pages of an 80 page book, so there will be more development for why things happen the way they do. Also It is Part 1 of 3, so we have seen less than 1/6th of the series.
-We know that Zuko does not stay like this, we know from Korra info that he and Aang together found Republic City Together. So he behaviour is only temporary.
-Zuko is not fully developed as a character as we end the show, yes he has found his destiny and path, but there are things that he still has to get over. Ozai has 2 things Zuko needs: Information on Ursa and knowledge about being the Firelord, as long as Ozai knows these and Zuko doesn’t, Ozai has some power over him. Look at the stress he is under, Iroh obviously retired and at his tea shop in Ba Sing Se, assassination attempts on his life, running a nation has kept him away from his friends. You can see why he is acting the way he is, what Ozai wants and how Zuko reacts to that will be key.