Thinking about how Zuko seems to understand Aang in some ways better than the rest of the gaang in a very short time. Recently rewatched the finale (finally finished getting my grandmother to watch the whole show, she loved it), and when Aang was having his argument with the gaang and then left, Zuko stopped Katara from going after him and said "He needs time to sort it out by himself."
Something I've long since noticed is that one of Aang's and Katara's conflicts is that they approach problems very differently, which leads to Katara trying to comfort Aang in a way that doesn't help or Aang trying to advise Katara in a way that doesn't help. Now, before I go on, I want to clarify, does this make kataang a bad ship? Not in the slightest. Couples having a disconnect on forms of comfort is very common and the healthiest of relationships are ones in which the two learn to meet eachother in the middle and be who the other needs to be. Their conflict in this is realistic and usually shown to resolve itself as they learn to meet the other where they need them. I am in absolutely no way disparaging Katara or trying to say kataang is bad or worse than zukaang.
I'm saying that because I am going to delve deeper into this dissconnect between Aang and Katara in comparison to Zuko. Again, this is in no way me trying to say Katara is bad for Aang, all couples have their problems and zukaang absolutely has issues that kataang would never have. Please for the love of god do not take this the wrong way.
Now, back to the point, we do see a pattern throughout the show of Katara trying to reach Aang through words. She's a naturally caring person and just wants people to feel better, unfortunately, she's also 14, and thus not exactly a trained therapist, and Aang isn't receptive to that particular brand of comfort. In things like General Fong's pressure on the Avatar state, or Aang's stress after waking up from the coma, or Aang's shut down after Appa, she tries to reach him and convince him to feel better, which doesn't really work on Aang. (Usually. There are some times where it does work, like during The Storm).
She has a tendancy of trying to tell Aang she understands what he's feeling when she doesn't which just pushes Aang away. (A mistake Aang also makes with her, these are Children™ trying their best). Their disconnect comes from the fact that Aang approaches problems with a desire for a solution while Katara approaches problems with a desire to fix the emotion. Both valid, but not matching.
My zukaang brain rot ass has long since had the hc that Zuko would be a bit better on this just because of the way he approaches things. Zuko also approaches problems with a desire for a solution. We see that very clearly in his buddy-cop episodes with the gaang. He connects with each of them by trying to help them solve a problem.
I was not expecting my hc to be verbally confirmed by him though, didn't remember that part, but yeah, Zuko, within only a few weeks of knowing Aang, understands that Aang needs time to sort his emotions out on his own, something Katara still struggles to understand even after seeing it happen multiple times. (Again, she just wants to help, and it can be really hard to watch a loved one struggle, of course she wants to be able to say something that will fix it.)
Throughout the finale we see Zuko meet Aang where he's at.
The first example:
I know you're scared, and I know you're not ready to save the world. But if you don't defeat the Firelord before the comet comes, there won't be a world to save anymore.
He acknowledges how Aang is feeling and he doesn't tell him he should feel differently, he just points out very bluntly that there is a problem. Also, just the fact that he acknowledges that Aang could be scared. It's not really something that acknowledged much. Even during Nightmares and Daydreams when Aang is literally falling apart due to nightmares and fear of what's coming, the others are more concerned with just getting him to stop. Zuko tells him that it's reasonable for him to not feel ready where everyone else constantly insists he is ready for things (like the invasion).
(Of course, again, the others are also encouraging in their own right. When Aang is starting to spiral they assure him that he's not alone and that they can fight the Firelord together)
Then, when they're all having the arguement, Zuko, clearly being on the side of "hey kill the Firelord" still doesn't ever tell Aang what he should feel.
Aang: "But he's still a human being."
Zuko: "You're doing to defend him?"
"No. I agree with you. Firelord Ozai is a horrible person, and the world would probably be better off without him, but there's got to be another way."
"Like what?"
*Gluebending Idea Tangent*
"Yeah, and then you can show him his baby pictures and all those happy memories will make him good again."
"Do you really think that would work?"
"No!"
Zuko asks questions, lets Aang lead the conversation, and when he's arguing against him, does not directly tell him he's wrong, instead tries to get Aang to see the faults in his own thinking. Zuko's approach to arguing with Aang is to get Aang to figure things out on his own, not tell him he's wrong. Even in the beginning when Zuko attacks Aang, he is trying to get Aang to understand that he's not ready and needs more training by showing him, not telling him. Zuko understands that Aang needs to be able to reach his own conclusion, not be told what his conclusion should be.
Meanwhile, the rest of the conversation goes sharply downhill as Sokka and Katara directly just tell Aang that what he says he's feeling isn't correct.
Aang: "I can't just go around wiping out people I don't like!"
Sokka: "Sure you can, you're the avatar. If it's in the name of keeping balance, I'm pretty sure the universe will forgive you."
Aang: "This isn't a joke Sokka! None of you understand the position I'm in!"
Katara: "Aang, we do understand, it's just-"
Aang: "Just what Katara, what?"
Katara: "We're trying to help!"
Which is another one of those situations I mentioned where Katara tells Aang she understands what he's feeling when she does not. She's trying to help, but that is not helpful.
Then, of course, the line I mentioned earlier.
Katara: "Aang, don't walk away from this!"
Zuko: "Let him go. He needs time to sort it out by himself."
Again, Zuko has only been there a few weeks, the water tribe siblings have known Aang for the better part of a year. Yet, Zuko tells Katara with certainty that Aang needs time and space, which he does.
I think there's also something to be said for the fact that Zuko, before anyone else, even Aang, noticed the conflict between Aang's values and his mission. When Aang says violence is never the answer in The Southern Raiders, Zuko asks (notably asks) what he's going to do when he faces Ozai.
Also:
Sokka, in response to Aang disappearing: "It's pretty obvious. Aang mysteriously dissapears before an important battle? He's definitely on a spirit world journey!"
Zuko: "But if he was, wouldn't his body still be here?"
Sokka: "Oh yeah, I forgot about that."
Like, Sokka, honey, baby, you've known this kid for nine months now, come on.
Anyway, there's a lot of subtle zukaang moments in the finale that I may write a post about later. I just really like Zuko's quick and inherent understanding of who Aang is as a person.