A villain from The Legend of Korra may have been more of an overarching influence than anyone realized, helping cause the Hundred Year War.
Avatar: The Last Airbender features many mystical beings that operate almost at mythical levels — influencing the entire world merely by existing. One such being is Vaatu, the spirit of darkness from the sequel series The Legend of Korra, In that series, Vaatu is revealed to have a deep history and connection with the world. But he might have had a more important impact than anyone ever realized.
It’s possible the approaching Harmonic Convergence could have allowed Vaatu’s influence to spread in the world before the events of his full release — and it may have played a role in the genocide of the Air Nomads that set the events of The Last Airbender in motion.
WHO IS VAATU?
During the Legend of Korra two-part episode “Beginnings,” the origins of the Avatar Cycle were first explored. The story centers on Wan, the very first Avatar from a long-forgotten era. During his travels through the Spirit Wilds while the rest of humanity remained safely on the cities atop the Lion Turtles, he eventually found himself confronted with a battle between opposing spirits. One of them, made of darkness, begged Wan for help to be free of the other. Wan complied, using his fire-bending to separate the pair.
It was only then Wan realized his mistake — he’d just freed Vaatu, a spirit of immense malice and darkness. Vaatu had been held at bay by the light spirit Raava, who’d intended to lock him away for another 10,000 years during the coming Harmonic Convergence to prevent the spread of his influence on the world. But now that they’re split apart, Vaatu can bring darkness to the world and grow powerful enough to instead entrap Raava. In his presence, spirits become more aggressive and the humans they attack become more violent and vindictive. He’s even shown observing and influencing a battle between the spirits and the humans where they both give in to their inner darkness.
All of this only empowers Vaatu more and more, spreading his influence even further. In only the span of a year, Vaatu has sown such discord and chaos across the world that he has gained a new and massively powerful form. But by fusing together into one being (the Avatar), Wan and Raava are able to defeat Vaatu and seal him away during the Harmonic Convergence — preventing his full spread into the world. By the events of Legend of Korra, those ten thousand years have passed, and Vaatu (working with the Water Tribe conniving chieftain Unalaq) prepares to make another attempt to break into the material world.
HOW VAATU COULD HAVE AFFECTED THE LAST AIRBENDER
But his plans might have actually also influenced the world of Avatar in a major way even before his identity was revealed. Less than two hundred years before the Harmonic Convergence seen during The Legend of Korra, the world fell into disarray because of the results of the Hundred Year War. After growing in power over the course of decades, Fire Lord Sozin decided it was time to expand the power of the Fire Nation. His best friend and Avatar of his era, Roku, resisted these ideas for their potential to throw the world out of balance. This fostered resentment between the pair, leading Sozin to eventually turn his back on his friend and leave him to die at the base of a raging volcano while Sozin escaped to carry out his plans for the world.
This embracement of darker designs is exactly the kind of influence Vaatu was previously shown having on the world and the beings who lived on it. A tribe of fire-benders was even shown giving into their anger and ambitions for their own lands in the past partly because of Vaatu egging on their conflicts. This could have been the same influence that ultimately pushed Sozin to betray Roku and launch the initial attacks of the Fire Nation on the rest of the world. In fact, his first assault was on the Air Nomads, as they would be the next nation to give birth to the Avatar — a decidedly dark plan to attack the core connection between Raava and the rest of the world, trying to cut it off before the Avatar could play a role their plans.
Although the Avatar would be needed down the line to fully release him, Vaatu influencing humanity would have severely hindered Raava and the world she swore to protect. Maybe it was the selfish impulses that Vaatu feeds and thrives on that pushed Sozin to doom so many lives with his actions. Sozin had in fact helped Roku evacuate the island before turning on him — a clear sign that he’d initially come to help, not to hinder. But being closer than ever to Harmonic Convergence, maybe Sozin decided to take the opportunity for power when it presented itself. If so, then Vaatu is directly responsible for the direction the Fire Nation took in the early days of the war — especially wiping out the Air Nomads and leaving a frozen Aang as the last of his people.