• how non-linear zuko’s recovery is. it would’ve been easy and dramatic to have zuko do his heel-face-turn at the end of series 2, because the whole season was dedicated to him finding a new place in the world and realising the wrongs of the fire nation. the fact that he actually hits rock bottom at the end of season 2 feels far more real, as well as sending a more important message. when zuko decides to help aang in season 3, it’s a decision he has made completely by himself, not because of circumstance or Iroh’s advice. he’s separated from his uncle, has regained his title of crown prince, and has his father’s (conditional) respect. he’s no longer outcast and making the best of a bad situation, nor doing what his uncle suggests. his time in the earth kingdom with Iroh informs his character development, but at the end of the day, he is the one that manages to get himself out of his toxic mindset, which is one of the most powerful messages about recovery I’ve seen in fiction. 
• the way aang and katara’s relationship is handed in season 3. while ‘the day of black sun’ does fall into the trope of aang kissing katara out of nowhere as a bold romantic gesture, I adore that in the ‘ember island players’, when aang tries to kiss her again, they actively challenge it. katara rightfully says that she’s confused and there’s too much going on for her to make sense of her feelings, aang kisses her anyway, and she pushes him away. it’s made clear that aang is in the wrong for disregarding her feelings. when they finally kiss again, it’s katara who initiates, and that teaches a subtle but hugely important message to children about consent. 
• the magic system is more than just a bunch of cool powers. each element is tied to a specific philosophy and way of thinking. we get the sense that aang achieving ‘balance’ is about more than mastering powerful abilities - it’s about spending time with multiple cultures, studying multiple perspectives on life, and finding harmony between them.
• while the energy bending introduction was a little bit of an ass pull, the final episodes raised an incredibly complex issue - namely, the debate of whether it is ever right to kill. given that it’s a kids’ show, I’ve never been in the camp of thinking that aang should’ve killed ozai, and think there’s a poetic beauty to the fact that - as the last airbender - he refused to relinquish the philosophy of his culture. but the fact that they broached such a controversial topic at all was incredibly bold.
• the fact that the characters change appearance throughout the show. it makes them feel far less static, as well as being a great device for conveying the passage of time. 
• starting from season 2, they introduce much more variety in motivation among the villains. the fire nation aren’t the only antagonists. we see earthbenders who forcefully trigger the avatar state because they want to end the war as quickly as possible, waterbenders with personal, indiscriminate vendettas, spirits who are removed from human conflicts and wish to protect their own interests. throughout the whole series, we see conflicts between the villains - zhao and zuko competing to catch aang, azula and long feng competing for control over ba sing se. it adds so much complexity and intrigue to the story. 
• azula is a hammy, fun-to-hate villain who also manages to feel raw and human. her backstory explains her actions without justifying them. even though we start the series with the utmost sympathy for zuko, by the final series, we come to the realisation that his imperfections and exile are the only things that saved him from becoming like azula. they could’ve made azula’s takedown into a kickass moment full of schadenfreude, but instead it was harrowing, dark, and undeniably tragic.
• every single member of the gaang has their own strengths and weaknesses, such that the group would never be able to function without any of them. I particularly appreciate that sokka is never merely delegated the role of dumb comedy side-kick. while we do laugh at his misfortune a lot, his insecurities are thoroughly explored and his tactical skills are crucial throughout the series. he also undergoes a huge character arc rivalled only by zuko’s. 
• the writers don’t forget previous events and characters. aside from bringing them back for the invasion in season 3, previous characters are continually addressed, even if just via off-hand comments. I love that aang keeps mentioning hei bai despite them only appearing in one season. I love that kyoshi returns in the season finale to talk again about her conflict with chin the conquerer - as does the avatar who tried to slay ko. I love that Iroh’s redirection of lightning in season 1 becomes hugely relevant in season 2, along with his white lotus tile. I love that the library in which zhao discovered the name of the moon spirit becomes a key focus in the second season, rather than just being a vague plot device. it makes the whole avatar universe feel so much more real, precise and consistent. 
• iroh feels genuinely wise. he’s not just a tropey old man whose generic advice is treated as incredible wisdom. even though I first watched avatar as an adult, so much of what iroh says in the series genuinely resonated with me - particularly his point that pride is not the opposite of shame, but its source. he also has his own distinct history, goals, and personality. you get the sense that his wisdom has come from many years of setbacks and self-discovery.
• toph’s relatively unchanging character. while many of the characters undergo huge arcs, toph remains fairly unchanged throughout. she grows more comfortable among her companions and realises she doesn’t have to do everything herself, but, at the heart of it, she remains the blunt, stubborn, self-important little goblin girl that she was at the beginning of the series. given that toph has spent most of her life hiding her real desires and talents, this is exactly what her character deserved. it’s also an excellent metaphor for the unchanging nature of her element, earth. 
• the gaang never insist that they’re not children. one of the most annoying tropes in children’s shows is when the young protagonists constantly claim they aren’t kids (looking at you, storm hawks), but it is completely absent from avatar. the characters never try to prove that they’re more mature than they are - aang openly acknowledges that he’s just a kid, multiple times. okay, katara does sometimes take it upon herself to be the mother of the group, but the writers explore why that is, as well as making it clear that she’s just as much a child as any of them. I think it’s so important for young viewers to get to watch heroes who are every bit as silly and childish as they are, but who still have real complexity. I also think it adds huge appeal to older viewers, because we never have to roll our eyes at a bunch of bratty kids insisting they’re aren’t children. 

“Ringo isn’t even the best drummer in the Beatles”

• “I meant to learn about cars, and then I forgot.”
• “I have a girlfriend now myself, which is weird because I’m probably gay based on the way I act and behave.”
• “I could never dress goth, and don’t get me wrong. I’m unhappy, it’s not that.”
• “It is 100% easier not to do things than to do them. And so much fun not to do them! Especially when you were supposed to do them.”
• “Whoa! That tall child looks terrible! Get some rest, tall child! You can’t keep burning the candle at both ends!”
• “I was raised Catholic. I don’t know if you can tell that from the everything about me.”
• “I thought I was gonna be murdered my entire childhood!”
• “What is college?” *incoherent babbling*
• “I was sitting up in bed a few weeks ago like [groans]. You know, life?”
• “When I walk down the street, I need everybody, all day long, to like me so much.”