I am BEGGING Atla fans to stop trying to look for some ulterior motive Aang had with not killing Ozai.Aang didn't kill Ozai-dosen't kill anyone at AT ALL and NEVER SHOULD and NEVER WILL because HE'S A BUDDHIST!!!!!!!! No geek ass who's never even eaten authentic asian food instead of weeb shit has a say in a millenia old eastern religion,no speakie pookie!!!!

If elements were more lineage based and not stuck 1:1 per parent what element would you hc the air kids as having. (Assuming Pema is a non bending daughter of at least one earthbender)

//Personally, I've always imagined Pemzin's kids as having the potential to be Airbenders (bc of Aang being of Air Nomad decent), Waterbenders (bc of Katara being of Water Tribe decent) and Earthbenders (bc of Pema being of Earth Kingdom decent). If one of Pema's parents were from Fire Nation decent, then I'd include that as well.

But I imagine it not extending past grandparents, because the creators specifically say it's not about bloodlines, but rather a spiritual connection, with each culture providing a different spiritual vantage point. So, while I do believe in some genetics having to do with ethnic grouping, I still think grooming is an important factor. By fostering the Air Nomad side of their heritage, they are more likely to develop into Airbenders than any other element.

With this in mind we know of three canon aspects that attribute to being able to bend: ethnic grouping/cultural upbringing (decides which element you're predisposed to developing), spiritual connection (how likely you'll be a bender), and a physical aspect having to do with blood flow and chi channels in/around the brain (an on-and-off switch basically).

Here's a snippet of an interview Bryke did for avatarspirit.net (the main online community for atla/lok content before tumblr arrived) that supports this. This is from April 2007. I've bolded the text I found most relevant.

RM: Okay, next I know I'm going really left brained and you can call me a geek because I am, but in "The Fortuneteller" you have a pair of twins...kids...one is an earthbender and one isn't. So is bending genetic, or is it some sort of spiritual thing? How does it work? BK: Mike and I just got new puppies. They're brothers. They have the same mother and father. Same litter. Mike's dog can just sit in a crate and be happy as a clam. My dog just loses all control...everything. Who knows why these things happen? They're beyond our full understanding. MDD: Yeah, Katara's mom and dad weren't benders. Maybe it's a recessive gene. I've always seen it as more spiritual connections, though. A little bit mysterious... BK: I mean we've definitely talked about it. I think, again, sometimes we might not know...it's more of what we don't want it to be. We didn't want it to be like there is a lineage...a royal family or something...and these people can bend and then there's everyone else as non-bending, people who never will. Some sort of caste system. Mike and I are more attracted to more of the flux type universe. The only constant is change, variation, that sorta thing. I'm sure it's a bunch of factors. ***Interviewers note: About 20 mins after the interview, Bryan came back to me and we spoke a little more about the basis of bending off recorder. He described bending as more of a talent. You have some genetic basis for potential, but you could go your whole life without developing the talent into ability. Some people have more inherent talent than others, while others with minimal inherent talent can still develop it through hard work and practice. He reiterated a connection to the spiritual energies is the underlying basis. How it manifests is based on upbringing and experience. RM: So could Teo's people perhaps grow into the airbenders of the future? BK: I think Teo's people are more refugees. They probably came together because they're not benders and really had no way to defend themselves. Then fell under this nutty guy who has his own skill and aura of authority. I don't think it's an ethnic group of non-benders, rather they were all just escaping the disasters of war. MDD: Yeah, I think if you've gone through puberty and not found any bending abilities, you're probably not going to find them. I think it manifests early. BK: Although that would make a pretty outrageous story. Some 80 year old guy... MDD: "Wow, I never knew!" BK: ...fire starts shooting out... RM: I was just curious if the airbenders could just come back from the general population rather than necessarily having to come back through Aang or anyone else who came from the airbending lineage. MDD: Aang is the last Airbender, so I don't think it's possible for Airbending to spontaneously develop in the general population. RM: It seems like all the Air Nomads were benders. Did they exile everyone who didn't manifest the trait, or did they really have such a high percentage of born benders? BK: We always have liked the idea of who will be a bender and who won't be to be kind of an ambiguous mystery, even to the people in the Avatar world. From early on we thought the Air Nomads would be all benders. Again it's like Mike was saying, it's more of a spiritual connection. But they have...they had...the smallest population. Earth Kingdom has the biggest population but the smallest percentage of benders. So yeah, there were these notions we kicked around that is wasn't going to be regimented or ruled through specific lineages. We liked the idea that each of the cultures have a different spiritual vantage point...coming at it from a different angle. MDD: Then the Air Nomads would have been the most spiritual...the most connected to the spiritual energy of the Earth. BK: But the most detached from society. More monastic.

Iroh did not Deliberately Lose the Siege of Ba Sing Se

I’ve seen this idea that “Iroh deliberately lost the Siege of Ba Sing Se” going around a lot lately, but it contradicts nearly all of Iroh’s canon actions and statements, along with the know author intentions of his character. Much more under the cut.

Winter Solstice, Part 1: The Spirit World”:

Earthbender captain: A place you’re quite familiar with, actually. You once laid siege to it for 600 days, but it would not yield to you.

Iroh: Ah, the great city of Ba Sing Se.

Earthbender captain: It was greater than you were, apparently.

Iroh: I acknowledge my defeat at Ba Sing Se. After 600 days away from home, my men were tired, and I was tired. [Yawns.] And I’m still tired.

“Zuko Alone”:

Iroh: (voice over) If the city is as magnificent as its wall, Ba Sing Se must be something to behold. (cut to a younger Iroh sitting at a desk, flanked by two guards, writing the letter) I hope you all may see it someday, if we don't burn it to the ground first. (He laughs at this, then cut back to a frontal shot of Ursa, the letter scroll spread open in the foreground, with Zuko and Azula on either side. They laugh with Iroh at this comment.)

“The Desert”:

Zuko: Ba Sing Se? ‌Why would we go to the Earth Kingdom capital‌? Fung: [Calmly.] The city is filled with refugees. No one will notice two more. Iroh: We can hide in plain sight there. And it’s the safest place in the world from the Fire Nation. Even I couldn’t break through to the city. [Happily shrugs his shoulders.]

“The Serpent’s Pass”:

Iroh: Who would have thought after all these years, I’d return to the scene of my greatest military disgrace … [Turns away for a second before turning back with a floral hat on his head.] as a tourist!

“The Crossroads of Destiny”:

Iroh: Many times, I imagined myself here, at the threshold of the palace. But I always thought I would be here as a conqueror...instead, we are the Earth Kings personal guests, here to serve him tea. Destiny is a funny thing.

“Sozin’s Comet, Part 2: The Old Masters”:

Iroh: [Aerial view of group.] Sozin’s Comet is arriving, and our destinies are upon us. Aang will face the Fire Lord. [Extreme close-up.] When I was a boy, I had a vision that I would one day take Ba Sing Se. [Cut to Zuko and the camera pans across to right showing Toph, Sokka, Suki, and Katara.] Only now do I see that my destiny is to take it back from the Fire Nation, [Extreme close-up.] so the Earth Kingdom can be free again.

…

Iroh: [Close-up.] Goodbye, everyone. Today, destiny is our friend. [Whispers.] I know it.

Note that Iroh is only talking to Zuko and/or the Gaang for the vast majority of these, and he never once implies that he didn’t mean to conquer Ba Sing Se; in fact, he establishes that he had a strong personal desire to conquer the city.

Now, let’s turn to authorial intention.

Interview with Bryke from between Book 2 and Book 3 of ATLA:

RM: I have to ask. Anything you can say about Iroh’s experiences after Lu Ten’s death and before he returned home to the Fire Nation capitol? MDD: He definitely had a ‘walkabout’, if you will, where he left the battlefield and had some sort of journey throughout the world after Lu Ten’s death and before he returned to the Fire Nation. BK: We’re seeing Iroh in his golden years, when he’s been softened by loss which has changed his perspective on what’s important to him and what’s important in life. As we’ve shown and had talked about, he was once a serious military giant, a very capable general, and he was very fierce. To me he’s such an interesting character because a lot of times people find themselves in situations which they happen to be very good at. He was born into this very powerful, aggressive family and just so happened to have a gift and the strength for it. But not all people are just one way, and he certainly had this gentle, kind side which appreciated life, all forms of life, and he could appreciate all cultures. If you look back on the great swordmasters of Asian history, a lot of them were artists, poets, masters of tea ceremony, actors, and the like. So I think when he lost something really near and dear, he went on a spiritual journey. He was lost and that other part of him was calmed. It’s not gone, it’s just not the most important thing to him anymore. RM: So he was a very different man before the death of Lu Ten. BK: Yeah. He was never a cruel man. But he was very good at what he did, and it was the role he was supposed to play. He went along with it, very successfully. RM: So he would have been ready to use his grandfather’s comet, Sozin’s Comet, to wipe out the Earth Kingdom if he hadn’t already done it the old fashioned way? MDD: My impression is that he would be more strategic. Maybe a little more 'inventive’. BK: Even back in the day he may have been into conquering, but… MDD: He was more the pragmatic military guy. BK: It was a job someone had to do. He didn’t take pleasure in it, at least not in hurting people, but it had to be done. Now it’s behind him. It’s really important to Mike and I on the show that these aren’t black and white characters. We love stories of redemption. That it’s possible for people to elevate to something better than they started out with, or maybe that they fell into. That’s really paramount to Mike and I. RM: Have you thought about what was going through Iroh’s mind when he got back home and his brother was on the throne? BK: Yeah, we’ve thought about that. He was tired. He’d lost his appetite for power struggles and military might. He was like, “You want it, have it.” MDD: He wasn’t going to put up a fight for it. He’d figured out during the journey what was really important. Being the Fire Lord was no longer on the top of that list. BK: He’d scaled down his perspective. He’d always dealt with the world, continents, and armies and navies. Now he was just honed in on Zuko as a sort of adopted son. If he could just help this poor boy whose father had kinda abandoned him.

I think this speaks for itself.  And of course we can turn to “Sokka’s Master”:

Warden Poon: You used to be the pride of The Fire Nation. Our top general. The Dragon of the West. Now, look at you. (drops the food to the floor. Iroh grabs a green fruit from behind the bars) Look what you've become.

You don’t get to be the Fire Nation’s “top general” without a lot successful conquest and imperialism under your belt.

And in fact even as late as Book 1, Iroh commits many clearly villainous acts. His ideological rejection of fire imperialism was not sufficient to change his behavior even at that point.

Moreover, I don’t think people understand the how horrific this idea that “Iroh intentionally lost the siege” is. Iroh opposes the war and doesn’t want to win it, so instead of making a public stand against the war(before or after the siege), he gets hundreds of thousands of people killed on both sides persecuting a siege he’s intentionally trying to lose? That does not make Iroh out to be good person.

As for why Iroh was allowed to to join the White Lotus:

A secret society devoted to the sharing of ancient knowledge and philosophy across national and political divides. Formed centuries ago by the wisest scholars from all over the world, OWL began as a club where these ancient masters could challenge one another on the Pai Sho table. They derived their name from the White Lotus tile used in Pai Sho, a key element in their favored strategy in the game. The elderly members include: Iroh (their leader), Master Pakku, Piandao, King Bumi, and Jeong Jeong.

Sozin’s Comet, Part II:

Piandao: We're all part of the same ancient secret society. A group that transcends the divisions of the 4 nations. Zuko: (Cut to a smiling Zuko) The Order of the White Lotus. (Cut to a frontal shot of Jeong Jeong and Piandao as Bumi comically slides into screen with a finger up in the air.) Bumi: That's the one. (Bumi comically exits the screen) Jeong Jeong: The White Lotus has always been about philosophy, and beauty and truth. (Cut to an overhead shot of the scene) About a month ago, a call went out that we were needed for something important. Pakku: (Cut to an area behind Zuko's shoulder looking at Pakku and Katara) It came from a Grand Lotus, your Uncle, (Cut to a close up of a smiling Zuko) Iroh of the Fire Nation. (Camera pans out to show Toph behind him).

The White Lotus are not a resistance organization! They’re a secret society dedicated to sharing knowledge who doesn’t bother doing anything concrete to fight back for 99.9% of the war. In fact, they act in an extremely dubious fashion even when they do fight at the end of the war.

In fact, given what we know of the authorial intentions surrounding Iroh in Book 2, it seems very possible that he joined long before he turned against the war.

As for why the White Lotus let Iroh join, three of its 5 known major members(including Iroh) are “redeemed” Fire Nation soldiers.  A fourth is highly questionable. And the final member is Pakku. This organization is highly unlikely to hold Iroh to any sort of “don’t commit genocide” standard.