Weekenders Adventures of Avatar: The Last Airbender - Sozin's Comet is an upcoming Weekenders/Paramount crossover to be created by Sonic876. It will appear on Google Drive in the near future.
Aang suddenly abandons his Firebending lesson with Zuko to have a beach party, causing Zuko to attack him in his frustration. Aang explains he plans to challenge Fire Lord Ozai only after Sozin's Comet and its enhancement of Firebending have come and gone, due to his own self-perceived lack of Firebending skills at the moment. When Zuko tells the group Ozai plans to use the comet's power to burn down the Earth Kingdom, Aang resolves to face him before the comet arrives. Sokka decides to have a simulation fight against a scarecrow, but Aang refuses to kill it due to his pacifistic nature and non-violent upbringing, and even berates his friends as they tell him that he may eventually have no choice but to kill Ozai.
That night, Aang sleepwalks to an island not to be found in the morning. After the group fails to locate him, Zuko takes them to June, a tracker who might be able to locate Aang. Meanwhile, Fire Lord Ozai proclaims himself to be ruler of the world, under the title "Phoenix King", and declares Azula to be the new Fire Lord, setting off to burn the world and rebuild it under his new order.
Zuko's tracker, June, is unable to locate Aang, but he is reunited with his uncle, Iroh, who reconcile with each other after Zuko's betrayal in Ba Sing Se. He and several other characters (Katara's Waterbending master Pakku, Aang's first Firebending instructor Jeong Jeong, Aang's Earthbender friend King Bumi, and Sokka's swordmaster Piandao) are part of an otherwise non-aligned group known as the "Order of the White Lotus", which plans to liberate the Earth Kingdom capital, Ba Sing Se, from Fire Nation rule. Zuko and Katara decide to fight Azula in the Fire Nation capital while Sokka, Toph, and Suki attempt to destroy the airship fleet.
Meanwhile, Aang awakens on a floating island. Frustrated with his inability to find a way to defeat Ozai without killing him, he asks four of his past lives for advice. Unsatisfied with their answers, he asks the island for help. The island, which is actually a giant "lion-turtle", provides Aang with the power of energybending and leaves him on the Earth Kingdom shores while Ozai readies his airship fleet for takeoff.
The Comet appears in the sky, and Azula's coronation takes place. Azula banishes nearly all of her subjects (including her Dai Li agents) in fear of betrayal, haunted by the actions of former friends Mai and Ty Lee in "The Boiling Rock, Part 2". Her paranoia and loneliness begin to drive her insane. Before she is crowned, Zuko and Katara arrive. Zuko accepts Azula's challenge of an Agni Kai, or "fire duel", because he feels that something is wrong with Azula and he does not want Katara injured. Just as Zuko is on the verge of defeating Azula, she shoots a bolt of lightning at Katara instead of Zuko. Zuko throws himself in front of her and intercepts the lightning, preventing Katara from getting hurt, but he gravely injures himself after he fails to correctly redirect the lightning.
Meanwhile, Sokka, Toph, and Suki hijack a Fire Nation airship, and use it to destroy many others, effectively stopping Ozai's plan of incinerating the Earth Kingdom. In Ba Sing Se, the Order of the White Lotus, led by Iroh, lays siege to the Fire Nation forces within the city, with the sole intention of re-conquering it in the name of the Earth Kingdom. Aang reappears and begins to duel the Fire Lord. However, when Aang successfully redirects lightning he intentionally aims it into the sky to avoid killing Ozai. Because of Aang's pacifism, Ozai begins to gain the advantage.
Zuko lies on the ground twitching as Katara and Azula fight. After several minutes of running and being unable to gain the advantage at first, Katara freezes Azula and chains her to the ground defeating her. Katara then uses her waterbending to revive and heal Zuko. As a result of her defeat by two people she considers less than worthless, Azula's mind finally snaps and she screams and sobs in fury, breathing blue fire out of her mouth, yet unable to escape her chains.
After a fierce battle, Ozai slams Aang into a rock, hitting the scar on his back from Azula's lightning in the previous season and inadvertently releasing his locked seventh chakra, allowing Aang to enter the Avatar State. With the combined power of his past lives, Aang quickly overwhelms Ozai. Once Ozai is subdued, Aang refuses to kill him, instead locking him down with earth; understanding the lion-turtle's meaning, he uses Energybending to strip Ozai of his Firebending powers, removing his ability to wage war. Then Aang raises and lowers the nearby ocean to undo the damage from the Fire Nation; Sozin's Comet vanishes beyond the horizon afterward.
The Order of the White Lotus liberates Ba Sing Se in the name of the Earth King. During his coronation, Zuko promises to aid the world in the postwar reconstruction. Sometime after the ceremony, Zuko visits Ozai's prison and demands he tell him the location of the banished Ursa, Zuko's mother. Zuko and Mai finally reconcile. Ty Lee joins the Kyoshi warriors, having bonded with them in prison and shared some chi-blocking techniques. A final scene depicts the main cast gathered in Iroh's new tea shop, the Jasmine Dragon, and with Aang and Katara officially confirming their genuinely strong and close romantic relationship with a loving hug and passionate kiss.