Zuko's thoughts while the haima-jiao was trying to eat him:
I am Prince Zuko. Son of Ursa, and Fire Lord Ozai. I've faced fire, and betrayal, and the Avatar himself. Exile didn't kill me. The North Pole didn't kill me. Azula didn't kill me. One of us is going to die here. It's not going to be me!
Iroh gets several, between his Papa Wolf status and Amaya, who, while an interesting character in her own right, was clearly designed to act as a foil for Iroh and heighten his awesomeness by comparison. Far too often, OCs are Mary Sues who get the character because they're just that special, and even make the character look bad so they look better by comparison. It was incredibly refreshing, and a CMOA for both the character and the fic, to see Iroh rescue the girl because he's just that pimp awesome, and then ride off into the sunset on the Avatar's bison leaving her wanting more.
In chapter 17, Dai Li agent Shirong becomes the viewpoint by which us readers are gifted with a deeper understanding of their order. It is the moment in which Shirong crystallizes as more than just another OC, causing this troper to actually empathize with him (much to this troper's surprise).
I am Dai Li. I've done horrible things to protect my city. I'll probably do a lot more. But this...
I am Dai Li, of the order formed to protect Ba Sing Se from its own spirits. By Avatar Kyoshi herself. And this horrible thing, I will not do.
In this troper's opinion, Kuei firmly takes his place as a character favorite by a statement that proves Kuei has what it takes to be not a good king, but a great king — by knowing and understanding his own people, Kuei is truly showing Earth's true heart: compassion.
"My ancestors may have been good, evil, or indifferent, but they were never charitable. I've read every agreement binding Ba Sing Se. I have to know what my people are bound to do." He ducked his head a little. "I tried to be a good king."
And then, there is Kuei's banishment of Wan Shi Tong and his servants from the Earth Kingdom:
You dare hold one of my subjects accountable for an outsider's actions? Simply because he, too, tried to help the Avatar? The world has been out of balance for a hundred years! It's the duty of every righteous citizen - no, every human! - to try to restore that balance. And every spirit! And you would pursue a petty revenge, against one of those trying to end this war? I believe your master has forgotten whose tomes contributed to his library. We shall see that he remembers it. We find you and your master, Wan Shi Tong, have behaved with contempt to us, and to our people! We find that you have done us harm; willfully, pettily, and with full knowledge of our desperation, beset by enemies! We find that you have cast aside the virtues of civilized creatures. And so, we render our judgment! You, your master, and all his servants are hereby banished from our lands. Your master may petition Oma and Shu. Should they decide his punishment is enough, we shall revisit our judgment. Until that day - begone!
"I have read about yāorén, Agent Shirong," Kuei said ruefully. "You need to train in fire, or someone's going to get hurt. And the only firebenders who've offered the Earth Kingdom aid, the only ones I'd trust with one of my Dai Li, are leaving." He smiled a little. "I know you all think I need to be protected. And I guess I do. But I also need to keep an eye on a great name. If I order you, will you go?" He couldn't speak past the sudden lump of hope. Wordless, Shirong dropped to his knees. "Get up, Agent Shirong," Kuei smiled. "Your family's waiting for you."
The escape by amphibious train, also in 36. Ty Lee gets one, though the readers see it from Zuko's perspective. Oh Crap.
"There are many reasons Sozin attacked the Air Nomads before the Earth Kingdom," Uncle had said once, on Wani's deck. "If you would capture the Avatar alive, we must take him before he masters earth. The union of opposites can be unstoppable." There wasn't time to duck. There wasn't time to plan. There was only an instant to move, hope no one was left in the car under them, and pray he could block enough of the shards. Dragon Chases the Moon. Fire surged from the burning roof; swirling vortices that didn't so much block the deadly shrapnel as catch and whirl it aside- Most of it. Oh fu- Pain.
Um, nearly every plot of Azula belongs here. Although admittedly, your mileage may vary, since Zuko seems to mess quite a few of them up. Still, she does the same to his plots, so it's only fair.
Wresting her mind from her great-grandmother's grasp in the latest chapter.
Ty Lee getting mad at Zuko for possibly dooming her people by trying to kill Azula and airbending to send back all the stone shards at him and Shirong. And then, when Azula asks her why, her answer? "You're my friend. And you're smarter than Fire Lord Sozin and Azulon. They hunted my people. You take care of us." Which may double as Crowning Moment of Heartwarming, if such a thing can exist in regards to Azula.
Although she had help, Ty Lee used her airbending against Makoto in the latest chapter, in such a way that not even Aang knows how to do.
Asagitatsu's awakening in chapter 53. That is all.
Chapter 60 where Katara finally stands up to Aang, telling him he's wrong about Hama, and driving it home to him what she really thinks of herself. The whole exchange between Sokka and Aang, once Sokka lost his patience with his friend:
"Aang." Sokka's voice didn't waver. But blue eyes narrowed with a determination that made Aang just a little uneasy. "I wish you were right, that talking fixed everything. I really, really wish you were. But we tried talking to Hama. We were with her a whole day. She knew two of us were Water Tribe; she knew we had a way to get into the Fire Nation. Which means she knew we had a way to get out. If she wanted to get away from the war, if all she wanted was to go home - all she had to do was ask us." "Maybe she was too scared to ask," Aang shot back. "Maybe she knew you'd figure out she ran away. And she was scared, and she just couldn't!" "This isn't about you." Aang almost jumped into a defensive stance. Sokka... Sokka sounded angry. Not just mad, in a who-ate-the-blubber-jerky way. Angry. "Hama was killing people." Sokka was breathing slow, like it hurt to; looking aside, past the flames. "We tried to talk to her. You tried to talk to her. She knew it was wrong. She was killing people because she could. Because she liked it. Because nobody knew how to stop her!" A low, hissed exhalation. "We stopped her. Maybe you don't like how we did it. Maybe none of us liked killing her, Aang, did you think about that? Because whatever she did, she used to be a person. And now she's dead, and she can't ever make up for what she did. That's one of the most horrible things I can think of. But there's something I can think of that's worse."
Chapter 65 is all Azula. Not only did she manage to stop the gAang with the fewest number of troops (some Home Guards and a handful of Onmitsu) with the minimum amount of casualties to the Fire Nation, she gave the Avatar a really good verbal smackdown...all without laying one finger on him. Azula actually decided to believe her brother and followed through with her plan. She may be a villain, and she may choose to be evil, but she remains a Magnificent Bitch.
A minor one in the same chapter for Sokka - working out Azula's likely tactic in time to save Hakoda from a lightning strike via thrown sword.
Chapter 66. Volcanic mudslide. That is all.
Chapter 68. Katara sees Aang fighting for his life against a very big dragon. She assesses the situation in seconds, right down to realizing it's trying to waste precious Eclipse time, then realizes the monster won't be able to resist "helpless prey". So she throws herself off Appa at several hundred feet in the air. And then bends the bay at it just before it can eat her.
Chapter 72. Zuko's battle plan for the defense of Dragons' Wings and the prevention of an eruption. Force Fong to lead his men into the only (bending) stable pass in the area. Hold the siege wall for as long as possible, using archers on the ridge to cull the numbers. When the wall is finally taken, run. Then, the coup-de-grace: Ignite the dry ice embedded into the pass. The ensuing explosion kills Fong and almost his entire army. Do not threaten Dragons' Wings. Zuko tends to get creative.
Further in chapter 72: Toph just out-badassed a quaking supervolcano.
Langxue chewing out Iroh for all his shit in chapter 73. As much as I love Iroh, he deserves every bit of tonguelashing from Langxue, and I hope Amaya punishes him too.
In chapter 78, Zuko encounters a sea serpent. He's alone, has broken bones, is floating on a chunk of ice and has the thing digging into his mind. He still comes out on top.
The whole Water Tribe sibling interaction doubles as a Crowning Moment Of Heart Warming as Sokka comforts Katara. He strikes a delicate balance of supporting his sister as well as pointing out that yes, she has made mistakes, this does not make her any less special. Special does not mean perfect, giving Katara exactly what she needs while not glossing over her major flaws like Aang is wont to do.
Chapter 80. Zuko bluffs a spirit that is basically this setting's version of a Pompeii worm at the Boiling Rock, a kanaloa, by telling it just how many things he's done that mean it does not want to face him. And it backs off.
"Ask your elder what I've done to the drowned. Ask the ocean where the sea serpent's bones lie. Ask who woke Asagitatsu! Do you think you can face me?"
It gets better, he was not bluffing.
As strong as the Fire Nation, and just as fragile. He knew how to kill it.
We are Fire. We are the blood of dragons. The only thing that can destroy us... is each other.
You forgot how he made his entrance and announced his status as not dead. That was also awesome.
Splorch. Squelch. Splish... Dripping from his black hair all the way to his pointy-toed boots, crazy bits of ice dropping off folds of soaked fabric, Zuko squished his way out of steaming water up onto the shore. Stomped past the still-twitching kanaloa, and glared at one unconscious airbender. "You have no idea how long I've been waiting to do that."
Chapter 81. Sokka calling out Shiyu for leaving Zuko in the dark about the location of the kanaloa, but mostly, ironically, this chapter is about Aang and how he's going to do things as the Avatar. He even calls Shiyu out himself for being like his Temple Elders, which I imagine, must be difficult, even if they tried to take him from Gyatso. Aang really grows up here.
Chapter 84. Pakku chews out Iroh over his insistence that Zuko leave with the Gaang to face Ozai. He even points out that Zuko TWICE had the opportunity to kill Azula, and did not do it, because she is his sister. And now Iroh expects him to help kill his father? Good on Pakku for reminding him that Zuko, is, in fact, a waterbender. With all the baggage that implies.
Chapter 85 manages to combine this with one heck of a Tearjerker. How so? Zuko says the below to Iroh, and Iroh doesn't answer.
"I am the Lord of Dragons' Wings," Zuko stated. "Either you are loyal to me, or you are loyal to the White Lotus. Choose."
Katara No Sells a spirit's mindbending of the entire colony.
Dig deep. Find the tides in your own blood. Feel the true pull of the Moon, away from haunted water.
Reaching into the well of her soul, Katara called up anger.
Fire on the ice. The stench of burning flesh. Grief on Dad's face, on Sokka's face...
Once this anger had almost torn her tribe apart.
This time, I'm going to save them.
Sokka nails smug, superior Ozai with the return stroke of Boomerang - resulting in Ozai's Karmic Death at the hands of the Drowned, the spirits of his own people whom he sent to the North Pole to commit genocide upon the Northern Water Tribe.
"It is your problem, Koh," Aang said steadily. "I'm the bridge between the living world and the spirits. I'm the one who sorts things out, so people and spirits can live together. And I'm telling you right now, your whole twisted game is over. You know they don't know what they did. You know there are humans who'd try to fix it if they did know what was wrong. And you didn't tell them. That means you're wrong." He crossed his arms, not flinching. "It's over. Now."
Chapter 90 cranks it Up to Eleven and then keeps right on going:
Katara creates a glacier and smashes the undead Sea Serpent to powder.
"Hey Toph!" Katara's grin was sharp and hard as an ice shelf. "Ever see a mountain made out of ice?"
Zuko goes one on one with Makoto in the Spirit World, forces her to retreat, and caps it off by healing Asagitatsu. And Asagitatsu returns the favor by annihilating the Drowned.
Riding the heated winds from Asagitatsu's (Zuko-assisted) controlled eruption, Sokka (on Appa), Teo, and the other airbending glider pilots take care of the rest of Ozai's airship fleet. By using hot air displacement to shove them out of the sky, into the waters of the bay.
Aang saves the entire world by cutting off Koh's influence. Without. Even. The threat. Of violence.