Everybody shut up I'm talkin' about steambabies/how Zutara get together.
Okay, so, Katara and Zuko. They go together to go find Ursa, yeah? They start having feelings in the midst. Like, they're holed up in caves while traveling, start talking about their pasts some more, start talking about the fact that one of them took lightning for the other, then BOOM, they're makin' out. They find Ursa, she's been hiding out in and protected by a village of airbender-descended nonbenders in the Fire Nation. But, Zuko and Katara DON'T get together. They decide to just stay friends, mainly because, yes, Katara gets to know and care for Zuko, but ALSO gets to know the Fire Nation, and learns from Ursa what it's like to be with a member of Fire Nation royalty. So, Katara puts Zuko down gently, knowing she wants to be her own person and figure out her own life, and Zuko's really disappointed, but obviously he's understanding. She doesn't tell him why exactly, just that they're still so young and they have other things to worry about at the moment.
Zuko becomes Fire Lord, Katara spends her time traveling the world once again, bringing all the different forms of waterbending she's encountered together, becoming a true master and creating platforms for the different styles and cultures to become more well-known. She returns to the Southern Water Tribe for what she assumes will be quite a while to take on students, hang out with her new nieces and nephews (Sokka and Suki gettin' bizzay,) and plans to avoid suggestions that she should take on a position as ambassador to the Fire Nation. They've had a few different ambassadors since she turned the position down initially (definitely just because she wanted to finish her life's work of collecting and returning SWT artifacts and becoming a true master of waterbending and NOT because she kinda wanted to avoid somebody...) but now that she's back and all she's really doing is taking on students and occasionally babysitting, she should be able to eke out some time, yeah? And, it's been years. There shouldn't still be anything there, right?
Welp, they get back in contact, and it only takes maybe half a year before they're dating. In that six months, Katara sees the wonderful work Zuko has done in the Fire Nation, how much more accepting they seem to be, not just of her, but of other cultures as well. Zuko's reforms in schools have created such a better atmosphere, and Katara can tell that the Fire Nation is in a better place to accept her. And Zuko makes it clear that Katara's dreams and ambitions will still be at the forefront in her life: although she'll have political sway, she won't have the same responsibilities to specifically the Fire Nation as Zuko does as Fire Lord. So, they date, and the Fire Nation is primarily supportive (Katara has been taught in schools as being part of the group that freed the Fire Nation from the grips of nationalism and fascism, and although there is still a group of Ozai Supporters, they are a much smaller and quieter group now,) and eventually, Katara and Zuko get married. Fire Lord Zuko is, of course, entirely devoted to his people and to enacting ongoing reparations for a hundred years of pain and sorrow caused by his ancestors, while Katara continues taking on students, acting as an ambassador for the SWT, and becomes a cultural icon within the Fire Nation, single-handedly encouraging many people from waterbender cultures to move there and diversify the nation. Then, Katara gets pregnant. The Fire Nation rejoices, ready to meet their future Fire Lord.
Katara gives birth to a waterbender. Cue just mass CHAOS in the Fire Nation. Suddenly, the cracks begin to show. Yes, you can create some change, or at least the appearance of change, in years, but it takes much longer to really, really create lasting differences. Sure, the Fire Lord can marry who he wants, and she can be Princess Katara (Katara hates being called Princesa Katara and only lets people use it when it's culturally significant, like in certain ceremonies) but our future Fire Lord CANNOT be a waterbender. It's FIRE Lord, not WATER Lord. The Ozai Supporters begin to infiltrate these new groups that are patently AGAINST their oldest son taking on his birth right and becoming Fire Lord someday. How can a waterbender ever understand how to best govern a nation of firebenders?
They eventually have another child, a girl who's a nonbender. The nation clings to her, begging their Fire Lord to skip over their son and bestow the birth right to her. Of course, their daughter has little interest in politics, and while they attempt to shield their son, he is very soon exposed to the prejudice of his own people against him. They had always planned to bring up their children in a mixed bending environment (which, considering the original show, is still a very new thing, since most couples we run into either share their bending or are a bending/nonbending couple,) and they uphold that promise, having both the palace in the Fire Nation and a home in the SWT which they share time in. As their son grows, he loves his heritage as a waterbender, but feels a deeper affiliation to the people he knows he's born to serve (as his father puts it) one day. He's a lot like him: methodical, shy, interested more in politics than fighting, and ridiculously hard on himself. Their daughter is more like Katara: fiery, VERY interested in fighting, and wanting to travel and cut her teeth out in the wide world. She connects deeply with her Uncle Sokka and Aunt Suki who teach her a lot about what it means to be a warrior and how to sail. But, their son weathers the great storm his birth has caused and sees that he's been given an opportunity to further his father and mother's efforts to bring about cultural change, not just in the Fire Nation, but the whole world.
Eventually, years later, their son gives a moving and empowering speech about how, yes, he's been raised with waterbending culture, but the Fire Nation is his homeland. And, who can call the Fire Nation a land of only firebenders? That erases the (now non-secret) cultures of the airbenders who live among them, the many nonbenders who feel disenfranchised, and the new immigrants that have revitalized the culture that ONLY moved there because of the promise of their acceptance his mother represented. He understands what it's like for ALL people to live there, not just firebenders.
He finally wins the majority of people over and succeeds as Fire Lord. Their daughter takes after her uncle and aunt (and her father with his dual blades) and becomes a weaponry virtuoso, and their son is the first to suggest and begin creating a place where there is no cultural expectation of what bending you descend from, to mirror his own mixed bending upbringing, which would eventually become this universe's Republic City.
Please give me notes. Please yell and scream. Do you like? Do you hate? Let me know. Bye.