Thinking about how naturally Aang and Zuko fall into a dynamic in the Firebending Masters.
Like, Zuko joined them just a few days ago, yet their interactions are those of people who've been friends long enough to trust the other but also be sick of the other's bullshit. There's a familiarity with them where Zuko's life changing field trips with Sokka and Katara are him establishing a dynamic and friendship with them (which are also great don't get me wrong)
And I was thinking abt it and the meta I did an amount of days ago I can't remember where Zuko, despite his number one goal through books one and two being Aang's downfall finds himself helping Aang again and again. It's part of those subtle primers that Zuko's antagonism of the gaang is driven by an idea his father forced on him, but that Zuko subconsciously understands on some level that his place is by Aang's side, not against him.
And so you get to the Firebending Masters and nobody second guesses their familiarity. They do not act like people who only a few days ago went from being mortal enemies to allies. They act like they know eachother, are familiar with eachother, and we easily accept that because the entire show has been subtly telling us THIS is their natural state. THIS is what they were supposed to be all along. THIS is that unspoken thing we saw in the Blue Spirit.
Zuko never feels the need to please or prove himself to Aang. In fact, he actively still antagonizes him (but in a friend way now) like when Aang says the thing about an upbeat attitude and Zuko's like "fuck this shit". Aang asks for some of his fire and Zuko refuses which, was dumb to begin with, but the fact that he feels solid enough in his friendship with Aang despite, again, only being actual friends for a few days, that he picks pettiness over helping Aang, is a testament to their friendship.
Zuko is perfectly fine with grumbling at Aang and being petty and doesn't feel the need to prove anything to Aang because he already knows Aang accepts him, that Aang's opinion of him isn't going to suddenly sour, that Aang considers him a friend. Because, on some level, Aang's probably considered him a lost friend ever since the Blue Spirit.
The Firebending masters is the resolution of the Blue Spirit conflict. They were always meant to be friends, Aang knew it, and on some level Zuko did too, so as SOON as Zuko lets go of his father's ideas and Aang knows that Zuko has changed, they are friends, naturally, as though they've always been.