If Katara and Zuko were only meant to be just friends, then why was their relationship the deciding factor in The Western Air Temple as to whether or not Zuko joined the Gaang? Why was it the most difficult for Katara to forgive him? After all, theres going to be a Toph and Zuko friendship, right? Sokka and Zuko? Aang and Zuko? Yet they all forgave him very quickly. And Aang, as well as the rest of them, was almost killed by Zuko on innumerable occasions, but that didnt stop them from forgiving Zuko, and it didnt stop Katara from showing Zuko kindness in the caves! So, why does it matter? Why is there such significance? Because Zukos actions in the cave left very deep wounds in Katara. If youre still a skeptic, watch The Western Air Temple again, because she said it herself.
You and I both know youve struggled with doing the right thing in the past.
She and Zuko have kept it a secret, what happened in the Crystal Catacombs. Neither of them ever told a soul, and yet they both remembered it very clearly. Katara mentioned it just there, and Zuko had a flashback scene in The Awakening.
Part of Kataras anger at Zuko was really her anger at herself. She had let her guard down to Zuko when he had done the same to her. She mentions having done this to Sokka in The Western Air Temple.
The thing is, it worked. I did feel sorry for him. I felt like he was really confused and hurt. But when the time came, he made his choice, and we paid the price. We *cant* trust him.
So what happens if she lets her guard down again? Watch The Western Air Temple again, because Iroh said it himself:
Destiny is a funny thing. You never know how things are going to work out. But, if you keep an open mind and an open heart, I promise that you will find your own destiny someday.
And right after this flashback scene in The Western Air Temple, Zukos face fills the screen, and then the proverbial camera turns to Katara standing in his doorway. He now has that open mind and heart, and we have been shown that his destiny is Katara. The only thing in his way is the fact that her mind and heart have been closed off to him. But she will open up to him again, and realize that her destiny is not a twelve-year-old who is too young to know what love is. It is Zuko. If this were not so, then Irohs words would not have been placed where they were.
That episodeand the ones that followed it, particularly The Southern Raiderswouldnt have stressed their relationship that much so that when she finally did forgive him, shed just say something along the lines of, Hooray! Ive forgiven Zuzu and now I can go make out with Aang!