- This page is about the Earth Empire's invasion of the United Republic of Nations and subsequent attack on Republic City. For the Equalists' attack on the city, see Battle for Republic City.
|"There is a grave injustice that must be corrected. As you all know, after the Hundred Year War, Avatar Aang, along with Fire Lord Zuko, stole Earth Empire land and formed the United Republic. This land belongs to the people of the Earth Empire and it's time to take it back! Republic City will be ours!"|
|— Kuvira announcing her plan to invade Republic City.|
The invasion of the United Republic of Nations was the final event of the formation of the Earth Empire, as it attempted to annex the territories of the United Republic of Nations, thereby restoring the Earth Kingdom as it was before the Hundred Year War. Its primary battle took place in Republic City.
Due to Zhu Li's desertion of the military of the Earth Empire, she was able to warn Republic City that Kuvira planned to invade the United Republic of Nations two weeks after the liberation of the Beifong family took place. As such, the city's evacuation efforts were made mandatory under the guidance of Prince Wu and Pema, the United Forces were deployed to defend the city, and Asami and Varrick increased their production lines of the hummingbird mecha suits. Meanwhile, Kuvira had her spirit energy cannon be attached to the right arm of an enormous mecha suit, which enabled her to easily transport it to anywhere she desired.
Knowing that Zhu Li had inside knowledge about her invasion plans, she executed her plans a week before scheduled. The first to learn of this was an outpost on the border between Earth Empire and United Republic land, but the post and its occupants was obliterated by the mecha suit's cannon before anyone could report the imminent threat to Republic City. Her element of surprise was broken, however, when Team Avatar, still under the impression that the spirit energy cannon would be transported by rail lines, set out to destroy those and the weapon. Although Kuvira fired several times at them in an attempt to take them out, they managed to escape and warn everyone that Kuvira's arrival was imminent, despite the defenses of the city not being ready yet.
Forcing Republic City's surrender
An unstoppable weapon
Reaching the city, Kuvira halted her army at the defense barricade erected by the United Forces. President Raiko radioed Kuvira and ordered her to leave the United Republic's territory. She refused, however, and used her spirit energy cannon to demonstrate the power she possessed; with one shot, she sunk the entire United Forces' fleet stationed in Yue Bay, though the surviving crewmembers were swiftly rescued by airbenders. Pointing her weapon to the troops gathered before her, she forced Raiko to surrender, lest she would kill them all. As he gave up the city, Kuvira demanded he turned over his army and the Avatar over to her, while giving Baatar Jr. his location, so he could present Raiko with their terms to consolidate the surrender. Korra refused to surrender and reunited with Team Avatar, Tenzin, Suyin, and the latter two's families.
Kidnapping Baatar Jr.
Deducing that the only way they could destroy the spirit energy cannon was to take down the mecha suit carrying it, Korra, Tenzin, Bumi, Kai, and Jinora left on a stealth mission to kidnap Baatar Jr. from his airship and after bringing him back to Future Industries, they tried to force him to disclose the schematics of the suit. Although Baatar Jr. refused to talk, despite physical threats and emotional talks from his family, he relented when Korra threatened to make sure he would never see Kuvira again unless he could convince her to leave the United Republic alone. Refusing to live his life without the woman he loved, he radioed her and pleaded with Kuvira to retreat. Kuvira had the location of the call traced, however, and although she told Baatar Jr. that she loved him and that conquering Republic City was not worth sacrificing their life together, she aimed the spirit energy cannon at his location, a Future Industries' factory. The blast completely leveled the building and destroyed all the hummingbird mecha suits manufactured there, though the people managed to escape safely as Bolin used his earthbending to lift a huge piece of concrete.
Second Battle of Republic City
Slowing down the Colossus
With Kuvira and two formations of mecha tanks crossing the Kyoshi Bridge to their location, the group split up. Asami and Varrick recovered the wounded and retreated to Future Industries Tower, where a few of the hummingbird prototypes in Asami's office could be used. Team Avatar, the Air Nation and the Beifongs headed off to slow down Kuvira's advance. Along the way, Meelo spotted a paint shop and came up with a plan. With paint strapped on, the airbenders flew to Kuvira's mecha suit and bombarded the glass to blind her of her vision. Although the metalbender had water to spray the paint off, it proved to be a distraction as Bolin dislodged the mecha suit's footing with lavabending while the Beifongs, unable to bend the suit due to its platinum armor, wrapped metal wires around the legs. The airbenders and Korra then airbent at the suit to make the mecha suit trip and fall itself. In Kuvira's attempt to break free, she fired the spirit energy cannon wildly, sweeping the city skyline and destroyed the skyscrapers. Breaking free of the wires, Kuvira regained her footing and fired at Korra and the airbenders. Having lost the initiative, the airbenders and Team Avatar retreated back to Future Industries Tower.
With the progress of the hummingbird prototypes not going well, Varrick and Zhu Li climbed to the roof of the tower. Varrick used the tower to emit another electromagnetic blast. In a wide radius the blast disabled two waves of the Empire's mecha tanks but did not stop Kuvira's mecha suit. Baatar Jr. revealed that the suit was powered by spirit energy so it could not be stopped. At that point Lin arrived with Hiroshi Sato. He revealed that Future Industries had developed a saw that was able to cut through platinum and it can be deployed onto the hummingbirds with some electrical tinkering despite the weight of the saw. By cutting a hole large enough for a person to slip inside Kuvira's suit, they can destroy the weapon from the inside.
The benders returned outside to buy time for the hummingbirds to be completed. The airbenders and Korra attempted to distract Kuvira while the others used the buildings to stop the mecha suit. Kuvira again fired the cannon at the airbenders. Tenzin grabbed Jinora out of the way and were caught by Meelo and Ikki respectively. Meanwhile, Bolin, Lin, and Suyin toppled an entire building onto Kuvira's suit in an attempt to crush it, and while it was effectively buried underneath the rubble, the suit managed to free itself and rise again. Just as the suit was about to fire on the helpless benders, the hummingbirds—one piloted by Varrick and Zhu Li, and the other by Asami and Hiroshi—were deployed in time to gain her attention. Varrick and Zhu Li attempted to cut a hole in the back but were forced to back away as a mecha arm attempted to swat them. Their hummingbird was eventually shot down and the pilots forced to bail out. However, they managed to lure Kuvira to a canal, giving Korra the opportunity to waterbend at the suit and freeze it in its place. With the suit momentarily immobilized, the Satos maneuvered their machine to the mecha suit's right thigh and started to cut another hole. Kuvira ordered more power to free its cannon arm, while slowly but effectively started to break down the ice, while Hiroshi kept on cutting, ignoring his daughter's warnings about the imminent danger. When Kuvira managed to break the arm free of its icy restraints, the Satos only had a few seconds to escape. Instead of piloting them to safety, however, Hiroshi ejected Asami from the hummingbird suit, while he used those last seconds to continue cutting through the mecha suit's exterior. Kuvira used the freed arm to squash the hummingbird suit with Hiroshi still inside while Asami and the others watched in horror. When the arm was retracted and the destroyed suit fell away, a perfectly cut hole in the platinum armor was revealed. Korra, Mako, Bolin, and the Beifong sisters rushed inside the suit, narrowly avoiding being squashed by the hand themselves.
Destroying the spirit energy cannon
Inside the mecha suit, Lin and Suyin left to destroy the cannon while Mako and Bolin headed for the control room where the spirit energy was powering the suit. Korra headed upward to the command room to confront Kuvira. As Lin fought a guard, Suyin metalbent the ammunition out of rotation before Lin joined her to wreak havoc and cut off Kuvira's connection to the cannon arm. Kuvira attempted to reconnect but failed. Acknowledging the weapon was rendered useless, the Great Uniter ripped off the cannon arm, incapacitated the Beifong sisters inside the arm, and flung it and the cannon away to the Spirit Wilds. Immediately after, Korra busted her way into the command room and began dueling Kuvira in a close quarters battle.
Meanwhile, Mako and Bolin arrived at the control room. After defeating the engineers inside, the brothers attempted to shut the mecha suit down, but to no avail. With no other choice, Mako decided to destroy the power source with lightning despite its violent reactions if attacked unprovoked. While Bolin dragged the engineers out, Mako shot the spirit energy source with lightning. While attempting to exit the room, however, he was struck down by one of the reactions and knocked unconscious. He was narrowly saved by Bolin, however, who had returned to help his brother and ended up dragging him out of the engine room just as it exploded. The resulting explosion destroyed the mecha suit, knocking Mako and Bolin unconscious and interrupting the duel between Korra and Kuvira.
Kuvira's last stand
In the immediate aftermath an exhausted but still walking Korra dragged the unconscious Kuvira out of the destroyed behemoth. As the metalbender woke up, Korra declared the fight to be over and demanded her surrender to Raiko, but Kuvira flung a small boulder at the Avatar before she could finish. Kuvira ran into the Spirit Wilds and Korra gave chase. The Avatar soon found Kuvira standing atop the spirit energy cannon tied up in vines but pointing its barrel at Korra. Kuvira fired on Korra who dodged the beam but the cannon inadvertently started a reaction in the wilds. The spiritual energy surrounding them began bolstering the cannon's power to uncontrollable levels, overpowering even the manual shutdown lever. She was eventually thrown off and targeted by the cannon's wild entanglement. However, before the beam could kill Kuvira, the Avatar activated the Avatar State and shielded them both from the blast. The shield and beam collided as the reaction created a dome that covered all of downtown Republic City. Afterward the dome shrunk to its epicenter and a ray of light shot upward from the center of the crater. Tenzin remarked that a new spirit portal had opened up in Republic City as the spirits returned from the Spirit World.
As the defenders and Earth Empire soldiers searched for Korra and Kuvira, the two emerged from the portal. They were immediately surrounded by Earth Empire forces who threatened to attack if Kuvira was not released, though having understood each other's desires, motives, and actions, Kuvira ordered her soldiers to stand down, declaring that the battle was over. She acknowledged she owed Korra her life and that the Avatar had displayed power that was far beyond her reach, and readily gave herself up to Lin and Suyin.
Kuvira's arrest signaled the end of the conflict and the majority of Earth Empire forces. The United Republic government and the Earth Kingdom were restored, but in light of recent events, Earth King Wu declared his intent to abolish the Earth monarchy in favor of a democracy and the election of leaders in each of the kingdom's states, which earned Korra's support. After Kuvira was taken into custody, she was scheduled to be tried for her war crimes in the United Republic.
The invasion and resulting battle that followed took a heavy toll on Republic City. Train lines had been cut to prevent civilians from evacuating the city during the battle and, while much of the city had been damaged to varying degrees in the fight against the giant mecha suit, the downtown area and Spirit Wilds had been completely annihilated, as well as the emergence of a new spirit portal at its center. Rather than rebuild the downtown areas, Tenzin and President Raiko agreed to expand Republic City beyond its current limits.
The severe structural damage left the city bankrupt, however, and unable to deal with the following evacuee crisis, as there were insufficient resources to house and feed all the homeless citizens, who were condemned to retreat to a large tent camp outside the city. President Raiko's popularity took heavy blows due to his decision to surrender the city to Kuvira, which further poisoned his already testy relationship with Avatar Korra.
The destruction of the downtown area also sparked a violent turf war between the various criminal triads, as well as a conflict between the humans who desired to profit from the newly created portal into the Spirit World and the spirits who wanted to keep their realm safe from exploitation.
In spite of Kuvira's surrender, not all Earth Empire forces stood down, and most notably, Commander Guan held the southern forces under his control near Gaoling. This threatened to jeopardize the Earth Kingdom's democratic transition, and President Moon strategized with Avatar Korra and Earth King Wu to deal with the situation at hand. It was agreed that Kuvira, now a broken woman, would be temporarily released from custody in order to try to convince the remnants of the Empire to surrender; however, Guan's forces firmly opposed Kuvira, with the commander also revealing his intention to take over the Earth Kingdom through democratic elections rather than through conquest.
Guan's threat to the Earth Kingdom was compounded with Doctor Sheng's development of new brainwashing techniques using electromagnetic waves. Many citizens of Gaoling, as well as the Earth King himself and several of Korra's friends, were kidnapped and brainwashed, allowing the date of the election to be moved up before the Avatar could intervene. However, Kuvira escaped from her captivity in Zaofu and forced Guan into surrendering, leading to his removal from office, with the election timetable being rescheduled to a later date. Kuvira's actions in ending her own empire also led to a reduced sentence of house arrest after she admitted to her guilt in her trial.