If the premise of the original show (not just the last airbender but the last of his people) is upheld, Air Nomads are well and truly genocided, genetically and culturally.
Obviously the most logical and satisfying explanation would be for Aang to breed every female in the show and for Tenzin to have his own harem.
Genetically, Aang's children are 50% Air and 50% something else, and his grandchildren are 25% Air and 75% something else assuming no incest. That number is NEVER going up. The only way for it to go up is for Aang to fuck his daughter(s) to produce 75% Air incest babies, and even then it's a temporary reprieve without more incest. But the hard rule is a human population needs a diverse genetic pool of 2500 to 5000 individuals to prevent degeneracy, there's no way to cheat around this. A stable reborn "Air Nation" will be 0.03% Air and 99.97% something else. If Aang and his son get harems, their descendants will still need to get down to 0.03% Air (specifically 0.03% Aang) to be able to start fucking endogamously.
No single person can contain a culture (in no small part because a lot of culture is interpersonal), especially not a young child. Maybe Aang can tap into avatar memories to reconstruct the airbending martial art, but he can't do the same for other art and material culture. He knows next to nothing about Air Nomad lifestyle, not having been an actual nomad, he was a monk from birth. Aang was unable to motivate even his own children - two of the three don't give a rat's ass about the Air people. His lib female groupies want to meditate and sip lattes in a "conscious community", not to compost air bison shit.
Later, in Whorra, newly awakened airbenders don't want to drop everything and resettle in bumfuck nowhere. Aang the Avatar was a novelty, Tenzin the bender is not, they have benders at home. Tenzin threatened this soy-looking guy, and he still would not - wait for it - bend (badumtish). Tenzin was only able to recruit one young boy, the retarded princess, and the airbenders the Earth Kingdom was forcibly training in-house. Apparently no one wants to train as an airbender unless forced to. And still they're air temple monks, not air nomads.
We also don't know if reemerged airbending is heritable.
Now this is interesting:
Aren't they not meant to even have relationships? Isn't anng confused about his peenor feelings in it?
Whorra's season 3 says airbenders get weaker if they have worldly concerns such as sex. This means Tenzin is an extremely shitty airbender, being a father and a leader of a people and a councilmember of fucking Republic City! However, this also suggests that airbending monks are celibate runoff of the general nonpracticing nomad populace, which means bending strength does not get bred out. It's still a question if airbending talent can be preserved in a non-Air population of Aang's descendants, but it's a possibility. The martial art will have to be rediscovered.
Finally, culture must be living. Technology advanced leaps and bounds within two generations, but there have been no people to carry Air Nomad culture into the new age.
That Lion Turtle deus ex machina only comes out so Aang won't have to compromise his morals while saving the world.
What morals? Aang comes off as an autistic little shitwhore here, devoid of morals, empathy, and inherent childish goodness his character seemed to suggest throughout the show. "Killing is baaad! let's effectively castrate him and stick him in solitary for life!"
(Later, in Whorra, Zaheer's gang were sentenced to solitary and torture for life just for trying to kidnap Whorra, which retroactively shits on Iroh's character and the original show. Libs sure love torture.)
That's the point, there are none. If an airbender has sex with someone the offspring is either always an an airbender or other type of bender because of how close airbending is to the spirit world.
I know the wiki says this but it sounds sus.
- Aang was as close to the spirit world as possible, and his first son Bumi was a nonbender before the dimensional merge.
- Benders were trained in Temples - this would mean all children of the Air Nomads were taken away from their nomadic parents and raised in sex-segregated temples. This (1) is fucked up; (2) means that, as training takes time, children are learning the temple culture from monks and not the secular traditions of their nomadic parents.
- air bison are rather intelligent if not outright sapient; while it's safest to fly if you're an airbender, it's not a requirement, as evidenced by Katara and Sokka.
Looks like the lead writers never bothered to properly design the Air civilization, and then proceeded to fart incoherent shit when asked by interviewers or needing to give directions to sourcebook writers.
How can air benders be both vegetarians and nomads at the same time?
They have flying bison which travel around the world faster than the seasons change, they can migrate and live off the land. They can also drink and process bison milk.
OP:
And the avatar, the only person that can quantify this story using their past lives CANNOT because CONVENIENTLY that's also the exact time that the avatar lost that ability?
I'm not sure what you mean by "quantify", but Whorra (or any other Avatar) can't prove shit. She can say she got a particular piece of info from a predecessor, but you can't verify that.
Furthermore, wrt the genocide, no Avatar witnessed that - Sozin started the campaign after Roku's death, and the one alive during the time was Aang, who'd run away and hid; he only learns of the genocide in ep 3, and in ep 10 he's still hoping that the inhabitants of the Northern temple are Air people.
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On a side note, Whorra's dimensional merge must have had catastrophic consequences and killed many more people than Sozin.
The original series works because it doesn't have to answer this question, but any followup would have to.
It's not the only question a followup had to answer and shat the bed!
Another one is "what happens when the good guys win and the baddies are no longer in power". The original series is "plucky rebels against the world". Authorities in it are at best nasty and uncooperative and often outright evil, and Aang and company oppose them wherever they go.
And when "the good guys" win, turns out the replacement is worse. Notice how everyone who's anyone in Whorra is in some position of authority. Four of the five villains in Whorra (Amon, Tarrlok, Zaheer and company, Kuvira) have purely political goals and are less evil than their enemies. The one proper apocalyptic threat is Unalaq, but after Whorra kills him, she follows through with the apocalypse!
And Whorra (the show) kills a lot of people! It's a political show with an older character, and the Avatar's abilities as an intermediary between cultures, negotiation and reconciliation, should've come in useful. But Whorra is too dumb for this; so if you oppose the Globalist Avatar Empire, more often than not you're going to fucking die.