The Legend of Korra/WMG/Avatar Metaphysics and Reincarnation

For theories about other subjects, see The Legend Of Korra Wild Mass Guessing Index.

The reason Korra has trouble airbending is because of the lack of balance in the world
Oh sure, she is hot heated and materialistic, but those are personality traits that came afterwards. She originally could only firebend, waterbend and earthbend (at least consciously) because, of all elements, air was the one most absent from the world, what with there being only one airbender in the world when Korra was born. If the airbenders had not been killed off, there would had probably been enough "air energy" to prevent this kind of thing from happening.
 * It's actually because the creators of the original avatar wanted something completely different from what we'd seen from the original series, hence the opposite. Aang only knew airbending and needed to learn the rest of the elements. Korra only knew the rest of the elements and needed to learn airbending. Aang and co. had to Walk the Earth. Korra stays put in the City of Adventure.
 * Hand Wave and plot don't excuse the fact that an Avatar is unable to bend an element. Also; this troper posted pretty much the same thing on the Korra WMG page.

Gyatso, Iroh, and Tenzin are the same person, reincarnated
Basically, using the speculation that in this universe a friendship can span beyond lifetimes: One of those "friends" of the Avatar is always a Cool Old Guy mentor figure rather than a peer. Gyatso was "it" before the cycle was interrupted. A few generations later this spirit still hadn't kicked the mentoring habit, so Iroh took this role with his son, then later Zuko, and starting around the season 2 finale, Aang. Iroh could have died around the same time that Tenzin was born...
 * Possibly Jossed, Momo was supposed to be Gyatso reincarnation, the episode wasn't made.
 * Iroh is fire and would reincarnate into Tenzin, who is air. This matches the avatar cycle. That means there must be two Cool Old Guys somewhere between Gyatso and Iroh that never got old enough to be Cool Old Guys.
 * Aang was in ice for a hundred years, they probably just lived til about middle age and then died when the universe realized there still wasn't an Avatar around for them to be Cool Old Guys to.
 * There's a problem with eh avatar-cycle parallel. Gyatso should have died 100 years before the start of the main series during the genocide. At the start of the series Iroh was what, seventy? If Iroh is Gyatso's reincarnation there must have been another between them who only lived to be about 30. If there were two of them at least one must have died during childhood. Its possible, but it kills the Cool Old Guy deal and does lend itself to some Fridge Horror.
 * Cool Old Guy Earth=Bumi,Cool Old Guy Water=Pakku.
 * It doesn't quite count as reincarnation if they are alive at the same time. Also, personally I would like to think that there are cool old ladies to match.

When an Avatar dies, their Spirit Advisor takes the form that they most identify with.
Take a look at the four Avatars before Aang. Yangchen, Kuruk, and Kyoshi all look to be in their late thirties to early forties. Since Kyoshi lived for over two hundred years, it's unlikely she looked that good when she died. When an Avatar dies, their spirit takes the aged form that they always saw themselves as truly being. Roku chose his appearance due to his guilt over Sozin, Kuruk chose his form because he was that old when he was to be married (in order to spite Koh) and Yangchen and Kyoshi chose their forms because they just liked looking younger. Of course, the main reason for this guess is so it'll be plausible when Korra talks to Aang for the first time, and Aang looks and sounds the same as he did in the first series. (Don't worry, you'll still get to see old Aang in flashbacks.)
 * Alternatively, Kyoshi looks that way cause it was when she accomplished the most (put down a rebellion, stopped Chin, etc.).
 * There is evidence that a spirit takes the form of how the character likely thinks of themselves in their head, in the episode with Roku and Sozin's backstory, Aang's spirit is bald and is wearing his clothes from books one and two.
 * That would be awesome, but Zach Tyler Eisen is already way older than 12 now.
 * In the opener it looks as though Aang is a bearded early-middle aged man. This is probably when he was feeling his happiest, with a nice big family and a Shining City growing as he watched.
 * Alternatively, Aang could have taken the form when he was in his late teenage years for whatever reason (Maybe he first established Republic City when he was 18?). That way Zach Tyler Eisen can reprise his role as an older Aang.

The Show will Finally Explain how People become Benders
The original show was really vague on how exactly people become benders. The Legend of Korra will have to explain how the Air Nomads were repopulated and the Southern Water tribe of benders. It'll probably have to do with energybending, finally justifying its awful asspulliness.
 * Explaining Bending will be a bad idea; it would be like the Midi-Chlorians from the Star Wars prequels.
 * I agree, to an extent. My theory is that people have a genetic affinity for one element, and some people might not exhibit any bending ability without at least some training. Yes, the Air Nomads were basically wiped out, it doesn't mean there weren't any people left with the POTENTIAL for Airbending, it just means that the ACTIVE Airbenders were wiped out. Sky Bisons were supposedly wiped out, too, and Aang manage to find a herd of them, who's to say that descendants of Airbenders weren't found in present day? Maybe some of the monks shown in the Air Temple are descendants of Airbenders. Just because Tenzin and his family are the only Airbenders we see doesn't mean they're the only ones that exist. There's also precedent for this: in the original series, Katara was the only Waterbender left in the Southern Water Tribe, yet Waterbending is alive and well there by Korra. As long as the genetic potential's there and there's teachers available, the art can come back. Likewise, people with the potential for Airbending can exist, but there haven't been any teachers available until Aang restored the Air Nomads. Also, keep in mind that name, Air NOMADS. I wouldn't be surprised that, when there's a few more of them, they'll start wandering the Earth to look for those who can Airbend and slowly bring their numbers back up.
 * Er... We already know how people became benders. It was explained in the original series. The Fire Nation, Earth Kingdom, Water Tribe and Air Nomads all learned from other things/animals already innately able to bend an element (albeit in there own natural way). The Fire Nation learned from the ancient tribe of Sun Warriors who learned from the Dragons. The Earth Kingdom learned from Oma and Shu, who were a woman and man who learned how to bend the earth from badger moles so they could meet each other in caves. The Water Tribe saw how the Moon pushed and pulled the tides, and learned how to do it for themselves. The Air Nomads simply learned from Flying Bison.

The Avatar cycle goes Male Female
But not through each incarnation, through each element. So Aang male Air, last Air Avatar female Yangchen. Korra female, last Water Avatar male Kuruk.
 * Except that the unnamed Fire Nation Avatar before Roku was male.
 * What if the Fire Nation Avatar before Roku WAS female and just looked really manly/hid it? The character is unnamed and I don't recall hearing their voice or even getting a good look at their face.
 * This is essetially jossed with Roku and Aang: Male/Male. Every now and again, an avatar has a previous incarnation of the same sex. There may be a pattern including these "Gender cold boots", but what it is has not quite been established.
 * Read the OP's entire WMG again, including the parts outside the header. "Through each element," as in: the last water avatar was male, the current water avatar is female, the next water avatar will be male. Aang and Roku do not break this pattern as they are not the same element.
 * I actually thought about this theory when I was cooking up my theory on the inherited conflicts Avatars face. Since the Avatar is a position meant to represent balance, it'd make sense for the cycle to switch genders every time it goes through an element. That'd mean that the next Avatars would be a male Earthbender and a female Firebender. That has AWESOME written all over it :)

People other than the Avatar can reincarnate, but don't have to follow the cycle.
Mako and Bolin are the reincarnations of Zuko and Sokka, respectively.
 * Or maybe it actually does follow the cycle and Mako is Toph?
 * Or maybe it actually does follow the cycle and Mako is Toph?

The Avatar cycle follows the Four-Temperament Ensemble, with two twists.
The traditional correspondance is Air=Sanguine, Water=Phlegmatic, Earth=Melancholic and Fire=Choleric. But it is subverted here, running the opposite cycle than the Elemental Nations' one. Instead, the cycle goes Phlegmatic-Sanguine-Choleric-Melancholic, but with another twist: each time we pass from a Fire Nation Avatar to an Air Nomad, the cycle skips one temperament.
 * This gives: Phlegmatic Airbender (Yangchen), Sanguine Waterbender (Kuruk), Choleric Earthbender (Kyoshi), Melancholic Firebender (Roku), -New cycle: Sanguine Airbender (Aang) and Choleric Waterbender (Korra).
 * In addition, note that Avatars from the same nation follow the same pattern. Naturally, this means that the aforementioned Avatars were, for example, preceded by a Choleric Firebender, and that Korra should normally be followed by a Melancholic Earthbender.

The United Republic is the nation of Energy
When Aang removed Ozai's powers, he brought back Energybending into the world - a fifth form of bending, previously unknown and/or dormant. Later, he and Zuko created the United Republic - in essence, a fifth nation. Where previously there were four nations and four corresponding forms of bending, now there are five of each. Amon's new Energybending powers are just the tip of the iceberg. This also means that in order to become a fully realized Avatar, Korra will have to master Energybending as well.

Bloodbenders are as commonplace as benders of lightning and metal
Hama said that bloodbending could only be used during a Full Moon, but she may simply have been mistaken. First, what if she just wasn't that powerful of a waterbender? She figured out a new technique, certainly, but Katara owned her at bloodbending on the first try. Second, what if Hama was convinced that blood could only be bent during a Full Moon without experimenting further? A more powerful waterbender might be able to do it on the nights around a Full Moon. And third, what about scale? Hama was one woman, using bloodbending for a single purpose of vengeance. No experimentation, no other bloodbenders to push the art forward in new ways. Compare Toph and metalbending. During the first series, Toph could only metalbend in a very brute manner. During the new series, metalbenders are just a bottomless bag of tricks. Which isn't to undermine either woman's genius at their art, but a single person can't come up with every possible innovation.
 * Bloodbending could be very useful in medical treatment, especially surgery. Perhaps there's a bloodbending hospital in Republic City with a statue of Katara in front?
 * I can totally see a master Bloodbender being the Avatar equivalent of a Combat Medic or Emergency Medical Technician. Bleeding is the primary cause of death in the battlefield, a trained Bloodbender being able to keep a victim's blood inside their body to keep them alive would be a very worthy use of the power.
 * What if waterbender healing is actually basically blood (and other body fluids) bending on an unconscious level, and Hama simply discovered how to use it differently?
 * What use would be a medical skill that only works during the full moon?
 * More useful than something which never works? Besides, it might work normally without a full moon if you had a few benders co-operating.
 * Honestly, bloodbenders would make an excellent police force. All they probably need is line of sight and effect, and they could subdue opponents with even less collateral damage than the metalbending police force. However, it will probably be the most difficult to enter police force, because you don't want to teach headcases bloodbending. Unless the police force becomes corrupt. Or has Tarrlok using it as a Secret Police.
 * Halfway confirmed..

The Avatar cannot have his or her bending taken away.
The Avatar is totally defined by her ability to bend. Said ability cannot be taken away because it would completely upset the balance of the universe, so the Avatar is immune to this because spirits protect her.
 * Alternatively, taking his/her bending away could be as damaging as killing him/her in the Avatar State, it could be one of the ways to break the cycle. If so, Amon could be MUCH more of a threat than he seems, if his ability to take away bending is legit.
 * Alternatively, Amon knew that he couldn't take Korrra's bending and that is the real reason he didn't try. His goal was to scare her with the possibility.
 * Original poster here. It should also be noted that energybending is sort of a battle between the two spirits. Whoever has the strongest will wins. The Avatar is someone who has a very strong will. Amon may be able to easily and casually take bending away from the average person, but could he do the same to someone as strong and powerful as the average Avatar?

Getting rid of the Avatar spirit would have drastic spiritual consequences.
The Avatar serves as the connection between the spirit world and the mortal world. Getting rid of the Avatar spirit by killing the Avatar while s/he's in the Avatar State, or taking away the Avatar's bending, will have drastic spiritual consequences, possibly in the form of cutting off the mortal world from the spirit world.

The Avatar is reincarnated into a place that has had an effect on the previous Avatar.
Avatar Roku learned airbending at the Southern Air Temple, where he found a best friend in Monk Gyatso. Aang was either born there, or left by his parents to train there. Aang himself was discovered by Katara and Sokka of the Southern Water tribe, and the people of that tribe were the first ones he met after a hundred years. He even went on to marry Katara. Korra was born into the Southern Water tribe, so it's possible that the Avatar spirit seeks out a place that was important in its past life.
 * I like this theory. So we can expect the next Earth Avatar to be born in Republic City?

The different elemental Avatars also inherit a pattern to the conflicts they face, and acting upon their element's nature is what allows them to resolve these conflicts.
Bear with me, this is a long, LONG theory.

So far in the series, we have seen two elements repeating amongst the Avatars: Air(Yancheng/Aang) and Water (Kuruk/Korra), so I can't really talk about the other elements in-depth, just speculate. However, we already see many similarities in the conflicts that these Avatars face, and I've come to the conclusion that each element in the Avatar cycle presents the Avatar with similar conflicts. Let's tackle the Avatars by element:
 * Yancheng and Aang (Air): Both Yangchen and Aang were Avatars during times of great conflict, and they both managed to secure peace afterwards. Although Yangchen's methods were more extreme than Aang's, they both still dedicated their lives to bring peace to a chaotic world. Also, from at least a superficial point of view, Yangchen was the most spiritually awakened of the previous cycle's Avatars, just as Aang was, when compared to previous avatars and Korra, much more spiritually aware. Thus Air Avatars tend to be powerful in spirit, but destined to live through times of great conflict.
 * Kuruk and Korra (Water): Both Kuruk and now Korra have lived/live in times of peace which were brought upon by the previous Air Avatar. As much conflict as there is in Republic City, the fact is that the Avatar World at large is experiencing great peace after Aang finished the war with the Fire Nation, and Kuruk had an easy time of being Avatar because of the peace established by Yangchen. Thus, both Kuruk and Korra have shown similar attitudes to being the Avatar: they have basically shown an entitled attitude to the whole thing, and been arrogant and cocky. They also have had three major sources of conflict: their arrogance, their lack of spiritual awareness and their love life. Kuruk's arrogance and lack of spiritual awareness is part of what made him attack Koh(not realizing how BAD an idea it was) and this led to Koh taking Kuruk's wife away from him, dooming him to an eternity of unhappiness and seeking vengeance. As for Korra, we have already seen that her cocky attitude has landed her in trouble, and that her lack of connection to the spirits has already affected her: she has not been able to perform even the basics of Airbending(the most spiritual of the four basic bending disciplines) and has reached young adulthood without being able to connect even ONCE with her past lives. She has even been in moments of mortal danger and not been able to enter the Avatar State. Also, her main enemy, Amon, claims to be guided by the spirits in his mission, which if it is true, then Korra is at a disadvantage to face him because of her lack of connection with the spirits. Think about it, would Aang have been in doubt about Amon's connection to the spirits? No, he'd have meditated, astrally projected and confirmed the truth himself. Korra is unable to do this. Finally(phew!), there's their love life. Both Kuruk and Korra have been caused great grief by their love life, Kuruk by his wife being taken away from him and Korra for having Mako(at least for the moment) taken away from her.

So as you can see, both Aang and Korra have faced similar circumstances to their predecessors within their element in the Avatar Cycle.

Now, let's analyze the elements themselves, and how the show so far has portrayed their strengths and the characteristics of their nations:
 * Air is the element of spiritual power and inner peace. Airbenders tend to strive for enlightenment and bringing peace to their world, and the Air Nomads are peaceful and given to monastic pursuits.
 * Water is the element of healing and nurturing. Waterbenders are most powerful in service of others, specifically in protecting them and healing them, and the Water Tribes value family and community.
 * Earth is the element of stability and order. Earthbenders tend to favor law and order, and the Earth Nation is powerful in its adherence to tradition and law.
 * Fire is the element of passion, physical power and action. Firebenders are most powerful when being decisive and proactive, and the Fire Nation has long been a nation of ambitious individuals.

Finally let's compare the Avatars we know to the characteristics of their elements:
 * Yangchen and Aang (Air): Both Yangchen and Aang had what we can call successful lives. They both followed the characteristics associated with Air, and it served them well. They both brought lasting peace to the world and had fulfilling lives. In Aang's case, he even brought back Airbending from extinction.
 * Kuruk and Korra (Water): Both Kuruk and Korra(at least so far) have had unsuccessful lives. Instead of being nurturing and willing to serve, they have been egoists, which has both led to them being too linked to earthly concerns to be able to connect with the spiritual and has led to loved ones being hurt.
 * Kyoshi (Earth): From what we saw of Kyoshi, she was a staunch defender of justice and order, and she thus had a successful life. She is widely recognized to have been an excellent Avatar.
 * Roku (Fire): Roku was indecisive, conflicted, and preferred to live away from earthly concerns, and thus he had an unsuccessful life. Distancing himself from his responsibilities and hesitating on doing what was necessary(killing Sozin) led to one hundred years of bloody war.

So that is my theory: each Avatar faces similar challenges to Avatars of their same element previously in the cycle, and the way they can be successful at tackling said challenges is to be true to the nature of their primary element. While every Avatar must master every element, it is the element of their birth that truly defines them and serves as a path to better serve the world. When Avatars serve their element's nature, they achieve great things, while going against their element's nature causes them much grief. Part of my theory is that, yes, the Avatars must master all the elements of Bending, but they also must serve as representatives of their element, show why their element is necessary. Also, the next theory here is a second theory that complements this one.


 * This is a very in-depth analysis and I can agree with everything. Right now, as the series is progressing, Korra is showing the Character Development to being an excellent Avatar with the lack of an ego in late episodes and even has been showing a nurturing side as to suggesting Mako be there for Asami to have a shoulder to cry on. Is this sort of why Tenzin gave Korra the task to babysit the children?
 * I don't know if Tenzin is aware of it, but it wouldn't surprise me, and I do think that Korra's character development will turn her into a more nurturing and protective person, we're already seeing shades of that. Korra's been blessed with, apparently, being a prodigy amongst Avatars in how quick she's been able to master the elements, but she lacks purpose right now. I think that protecting Republic City and her friends is what will drive her to be a paragon of what a Water Avatar is, and give her the tools to awaken spiritually and have a sense of purpose and responsibility. That's part of the reason I suspect Katara will have a much bigger role than just her cameo at the beginning of the first episode, especially when Korra gets serious about mastering Airbending. Not only would she able to commune with the Avatar spirits and meet Aang, she can also learn from a woman who was his wife, who lived through what he lived through and who can give a different perspective of his achievements(through the eyes of a Waterbender). Also, my theory is that one of Korra's friends being in mortal danger or getting seriously hurt is what will finally trigger her Avatar State.

An Avatar does not only bring balance between the elements, he/she also brings balance between Order and Chaos
In the current history of consecutive Avatars that we know of(Yangchen, Kuruk, Kyoshi, Roku, Aang and Korra), we can see another pattern emerging: Avatars also serve as agents of balance between Order and Chaos, not just the elements, and when an Avatar takes it too much in one extreme, the next Avatar takes it in the opposite direction. Let's analyze each Avatar individually:
 * Yangchen: Yangchen, as mentioned in the series, was an excellent Avatar who brought an era of unprecedented peace to the land. However, I think she might have made things TOO peaceful. After all, she made things SO peaceful, her successor basically didn't have ANYTHING worthwhile to do during his tenure.
 * Kuruk: I believe Kuruk, in neglecting his duties as Avatar, let the world go into a state of Chaos. Without the threat of the Avatar to stop them, many people fell into corruption and crime, and the Avatar himself fell into great grief because of it. This shaped the tenure of...
 * Kyoshi: Kyoshi was a fierce defender of law and Order, and brought many a villain to heel during her time as Avatar. She founded the Kyoshi Warriors, one of the most respected and trusted groups of martial artists in the entire Avatar world, and she is widely regarded as an excellent Avatar. However, like Yangchen before her, she took it to the extreme: she created the Dai Li, which with the passage of time became one of the most corrupt organizations in the Avatar world, and who ruled Ba Sing Se with an iron fist under the illusion of maintaining order. This also stifled Ba Sing Se, making them become culturally stagnant and isolationist.
 * Roku: Roku brought Chaos through inaction. By not being willing to face his friend Sozin, he let the Fire Nation become the expansionist country it is by the events of the series. It became SO chaotic that there was the very real possibility that the Avatar cycle would be permanently disrupted.
 * Aang: Aang is the first Avatar we see reaching a balance between order and chaos. He was the one who managed to stop the expansion of the Fire Nation, but not through conquering it, but by giving it a fair ruler who's willing to coexist harmoniously with the other nations. Aang's tenure as Avatar was characterized by peace, yes, but also by great change and development in culture, politics and technology. With the creation of the Republic and the founding of Republic City, Aang created an environment where all the nations could coexist and feed of each other. It is a perfect balance of order and chaos: order as a guiding force to maintain peace and chaos as creative drive and diversity.
 * Korra: During Korra's time, we interestingly see imbalance on BOTH sides of the spectrum. We could consider Korra's time to be "balanced", but in reality it is a time of extremism towards both sides with no middle ground. On the Order side we have the Council, who try to maintain order in Republic City but by dubious methods, being generally led by ambitious and manipulative Tarrlok. On the Chaos side, we have the Equalists, led by Amon. At least superficially, Amon's motivation has merit: Benders ARE too powerful and have too much power over politics and society. However, his violent methods and "end justifies the means" philosophy bring nothing but chaos and fear to the populace, and his genocidal agenda against benders threatens to destroy the cycle as we know it. In between them, we have corrupt companies trying to make a profit by stamping their competition and rampant crime. This has caused all citizens, bender and non-bender alike, to live in a constant state of fear. It falls on Korra to bring both extremes back to the center: raise and inspire the non-benders and make the benders be responsible and judicious with their powers to benefit all, not just themselves.

So as you see, the Avatar is not merely a manifestation of the spirits in this world, he/she also serves to rectify extremes in Order and Chaos so that the world does not lose direction nor becomes stagnant.


 * So does this mean that Avatars Aang and Korra are the ones we are watching is because they are the ones who will succeed where all other Avatars failed?
 * Well, yes, according to my theory, that is most certainly the case. And I made this theory before reveal as the bastard he is, which shows that indeed the world is becoming one of extremes(hell, the EPISODE ITSELF is named "When Extremes Meet"), so I think this gives even more credence to my theory. Also, remember that woman amongst the non-benders that were being taken away by the police? "You're OUR Avatar too!" Yes she is, yes she is.

Bending has a spiritual component which gets taken away when one's a victim of Energybending
Bending is not simply the ability to control the elements, it is the user using his spiritual power to bend them to his will(hence the name). When one's a victim of Energybending, one LITERALLY loses a piece of one's self. Look at the victims of it so far(Ozai, Lightning Bolt Zolt and Tahno). They're more than distraught, they're downright DEFEATED. They have literally had their very soul violated. This gives Energybending a much more urgent and sinister quality. I certainly can't see Aang ever doing it again. He only used it on Ozai because to him the alternative(killing Ozai) was even worse in his mind, but he can't possibly have not felt regret over it, especially since he actually made contact with Ozai's very essence when he did it. He sure as hell didn't teach it to anybody.

If Amon's Energybending is legit, then him using it so casually takes on a whole other level of horrifying.


 * Well, bending is a highly spiritual thing.

The ability to bend is not a genetic trait and doesn't depend on a person's spirituality but on the spirits themselves
There are two different ways this could work:
 * A person gets the potential to bend from the local spirits, for example if a spirit is present when a child is born they can chose to "bless" the child with the ability to bend whatever element the spirit is associated with. The child would learn how to bend from either an animal that was also "blessed" by the same type of spirit (badgermoles, sky bison, dragons, ect.), a physical form of the type of spirit that "blessed" them (the moon, the lionturtle,ect.), or another human who already learned how to bend. That is how only one of the identical twins from the previous series could bend but not the other, the spirit could only give their gift to one of them. Whether or not the parents could bend may help increase the chance of a spirit giving them the gift but it would be due to them having the ability to teach them as oppossed to genetics. That's also how Amon learned how to bend from a spirit, the spirit gave him the gift before hand and taught it to him later since no one else could just like how the lionturtle had to teach Aang spiritbending himself. It's also why we see very spiritual people with no bending and benders who are not spiritual people, it all depended on the spirits to be present and what they decided to do.
 * If bending tied into a process like the avatar cycle than it could also be a case of an individual spirit chosing to live as a mortal with the same skills they had as a spirit, much like how the moon spirit lived inside Yue. The spirit is born into whatever population of the species of their chosing (human, badgermole, skybison,dragon,ect.) that lived in the local area they were in, and many spirits of the earth, water, air, and fire elements chose to be humans. If a species died out, like what almost happened to the dragons and sky bison, they couldn't be born into it anymore so many spirits chose to be human due to its large numbers and it was the least likely to be wiped out. The earth, water, and fire spirits feel safe enough to continue to be born as humans despite the previous war but the air spirits chose to stay into the spirit world because they are still traumatised by what happened to them as airbenders, with the exceptions of the ones who chose to be desendents of the avatar himself since that would be the safest postion they could think of. This second theory may also explain how Amon thinks he can completely get rid of bending, if spirit bending is like an exorcism that returns the spirit to the spirit world without killing the human they were born into he might be trying to make the spirits scared to live as humans anymore due to the persecution they would face like what happened to the Air Nomads.

All Avatars have an animal guide.
Aang once commented that Fang the dragon was Roku's animal guide, just like Appa is to him. This implies that an animal guide is either common or mandatory. I propose a theory that all Avatars have an animal guide, though the animal doesn't necessarily have to be a bending one. Remember that the Avatar serves to connect the spirits, the people, and nature. Having an animal guide gives them that connection with nature.

Airbending will have its own new branch of bending at some point in this series.
Like how firbending has lightningbending, earthbending has metalbending, and waterbending has healing, plantbending & bloodbending. Maybe it will be developed by Tenzin, or Korra, or possibly even one of the kids. My bet is on sound bending. After all, sound is just the vibration of molecules in the air, right? Plus, it'd be cool to see someone use sound bending to do things like unleashing sonic booms, incapacitating their foes with high pitch sounds, and disorientate people by messing with the fluids in their ear.
 * This idea has a lot of credence, in my book. In the first series, Aang had a tendency to be incredibly loud at times. (PENGUINS!!!) One could also use an ability like this for stealth: making one's footsteps softer (we've also seen Aang do this) or even dampening all ambient sound in a room (which we might have seen Aang do). The possibilities are endless; expanding them into something a little more concrete wouldn't be that big a leap. The only downside is that we now have Meelo fartbending...not so cool.
 * I wonder if the morally ambiguous airbending technique turns out to be vacuumbending.
 * Taking the air out of someone's lungs... eardrums ruptured...
 * There could also be Thermobending, where the Airbender can control the temperature in a certain location through an advanced application of airbending to affect atmospheric pressure and create cold and hot fronts in an isolated area. But since Airbenders are mainly pacifists, any overtly offensive and destructive advanced Airbending techniques would not have been created.

Pema's next child

 * Isn't the Avatar reincarnated at the exact moment of birth? In which trimester is Pema during the series? What if Korra dies and Reincarnates in the 4th son of Tenzin?
 * The avatar cycle doesnt work that way, Air was the last element and Earth is the next. So unless Korra dies and the next two avatars are stillborn or sucumb to SIDS that's not gonna happen
 * Well, it could still be possible if Pema had earthbender blood in her.
 * Katara specifically states that the unborn child is an airbender.
 * She just said the kid would be another bender, she didn't specify an element. Though airbender is still the most likely, since Tenzin, the father, is an airbender, airbender genes would likely be the most prominent. (depending on how bending genetics work)

The Avatar Spirit is dying, and Azula is to blame
When Azula killed Aang, the only reason that he and the Avatar Spirit continued to exist is because of Katara's timely healing. However, Katara could only fix so much. Azula's lightning blast caused significant damage to the Avatar Spirit, which is worsening over time, like a festering wound. Korra's problems with spirituality are a symptom of this. Eventually, the damage will become too much, and the Avatar Spirit will die. Maybe not during Korra's lifetime. Maybe not during the next Avatar's lifetime. But soon.
 * However, if they manage to figure out something's wrong, they might be able to fix it. Perhaps relearning Spirit Bending might help.

Avatars can't lose their bending.
Their power comes from the spirit of the planet, which is how they bend all four elements. Aang wasn't in any danger of losing his bending when he de-bended Ozai, but of being corrupted, losing their soul, or dying. At no point did the Lion Turtle tell Aang that he would lose his bending. If they do lose their bending, they're no longer the Avatar; the planet's spirit moves on to someone else. It will be impossible for Amon to take away Korra's bending, because then he's dicking around with THE PLANET. Though if he manages to, Korra might be mentoring her replacement.

No one has any idea where the first Avatars were from
More specifically, they don't know what order the first four Avatars went in. While most Avatars are historically documented, the first few are figures of legend. All they really know is that while each of the four were awesome and powerful Avatars, the fourth one did something incredibly awesome, through the first recorded use of the Avatar State. Each nation has their own story on how things happened, ultimately favoring their native Avatar. (For example, ask a Water Tribesman, and he'll tell you that the order went so: earth, fire, air and water.) Only the Avatars know how things went down, and they're not telling.