Over the next few days the desperation he had felt during his previous visit was rekindled, doubly so with Toph around. She could sense when people were lying, and if she noticed anything she would call Aang out of it. If asked the wrong questions, things could go sour very quickly. Only this time, Aang didn't have the pressure of leaving. Zuko had made it clear that he wanted Aang to stay and help with the poor district, as he had begun the whole process by helping them with their issues. Azula confronted him, wanting him to simply tell her brother what was what, but Aang quickly stifled her arguments, saying that it was foolishness to try and force this down Zuko's throat. He would just fight it harder. It was best to wait for an opportunity. He had considered doing it the night of Zuko's successful attempt to cast lightning, but he decided he would wait. Zuko would think his gift was nothing short of a bribe to win his support of Aang and Azula's love. Aang wanted to maintain his friendships; he had gone through much with these people (even though Azula had been on the opposite side of the board at the time of the experiences.) Aang decided that if he didn't do something soon, however, Azula might do it herself. As such, Aang was preparing to enter the Fire Lord's chambers when he heard something very wrong. Giggling. It wasn't unexpected, given that Zuko had a wife, but the problem wasn't the sound itself, it was where the sound was coming from. It definitely wasn't his wife giggling. Aang was about to turn away when he heard a familiar voice from behind the door.
"Stop, Zuko, someone will-"
"No one will hear us, these walls are thick and stone."
Aang felt his heart shudder and cringe at the sound of the voice and what it meant. He was about to leave when he heard footsteps. Azula was walking down the hallway when she spotted Aang outside the Fire Lord's bedroom door. She smiled, knowing what he was about to do. She nodded and gestured for him to proceed. Aang shook his head when he heard something that made his heart stop.
"Of course there's no one in the hall, and even if there was, I don't think they could hear us. See, no one-"
The door was thrown wide, and there was Zuko, wearing absolutely nothing but a thin robe with the front wide open. On the bed, quickly covering herself with blankets at the sight of Aang, was a dark-skinned waterbender with long hair.
"Katara?"
Aang's voice cracked. His mouth hung open and he was shaking. Zuko covered his pride and stepped closer to Aang, putting a hand on his shoulder. Aang didn't feel it, nor hear Zuko's words.
"I tried to tell you, Aang. That night, when Azula and I came to see you. Then I realized Mai was pregnant, I thought it would stop, but-"
"Katara? Why?"
Katara said nothing, but her lower lip quivered. She knew this was adulterous and wrong, but Aang had never even seemed interested in her physically, he seemed so childish when it came to love.
Zuko spoke on, making excuses, talking of the cruelty of love. Aang heard none of it, he had eyes for only the woman who had broken his heart twice. He felt himself go faint. The blood drained from his face and Azula began to argue with Zuko, she yelled and swore and cursed and revealed her affair with Aang. Zuko began to snarl and yell at Aang, pushing him away. Aang staggered backward, not really registering anything. A single tear fell from his cheek. Azula and Zuko were so busy fighting that it took a minute for them to notice when Aang sank to his knees. Zuko watched and Azula followed his line of sight. She knelt next to him, holding him, comforting him. It made no difference. Aang was in a world of hurt and pain. He felt his body go numb, then burn hot then go numb again. His heart beat faintly, irregularly. Azula looked him dead in the eye, trying to get a response. Zuko tried to help but was swatted away by Azula, who stared into Aang's cold grey eyes. She leaned in and hugged him. A shudder ran through his boddy, quaking Azula along with it. She withdrew hoping to see some form of reaction form Aang. Instead she was met with two glowing eyes and a snarl that would make demons run for cover. Aang rose slowly, not even using his arms to push himself upright, he simply drifted upward.
Zuko ran into the room and grabbed the swords from where he had hung them. He strapped them on and drew them, preparing to defend Katara's honor. Aang heard a rush of sound and the past Avatars spoke to him. They whispered and shouted and spoke, causing him to realize what had happened. He had entered the Avatar state, and there was no way out until the Avatar spirit destroyed any and all threats to his immediate person. Aang saw Roku appear before him. Roka appeared sad and almost angry.
"Well, Aang, this must be a first. You must be the only Avatar in the entirety of existence who triggered the Avatar state because of a broken heart."
Back in the physical world, Azula stepped back from Aang. She knew all about the Avatar. He would destroy all that threatened him or his vessel. He floated towards the room, a sphere of air encircling him. The doors were almost ripped from their hinges from the wind. With a fatal boom they slammed close behind him, leaving Azula to pound on the door and yell for her lover.
Inside the room, Aang was beginning to unleash the power of the Avatar. An angry, feral snarl still contorted his features, making his appear as a Destroyer, not a Savior. Aang felt the hatred of a thousand angry beings course through him. His anger turned into power and his broken heart dying for a split second. His heart, which had been torn in two and now had one half thrown into the destructive forces of Katara's adultery. He knew he was just as guilty, but Katara didn't have thousands of people encouraging the brutal removal of the chains that bound Katara to him. She didn't have beings hollering in his ears for blood. She didn't have the voices of many past lives telling her to viciously destroy all who had hurt him.
Zuko swung his swords, directing a jet of lighting at the Avatar. But it was familiar with the tactic now, having died from it once before. The Avatar spirit drew from Aang's own knowledge, redirecting the lightning, strengthening it with the power of the Avatar and throwing it back at Zuko. It struck home, the power of thousands coursing through one, though without the protective measures of the Avatar state. Zuko was thrown into a wall, which cracked and collapsed on his. He was a huge, ugly gash across his bare skin and a large smouldering wound that was smoking and bleeding. His eyes were wide with shock and a bloody trickle ran down from his temple.
Katara shrieked in horror as the Avatar turned its attention to her. The face turned from anger to sadness to disgust. Back when things were civilized, when the Avatars before had lived, adultery was a most heinous crime. As such, Katara was looked down upon by the collective consciousnesses of the Avatar. Then something snapped inside of Aang. The Avatar as a whole cried out for her unpleasant and violent destruction. Roku joined the call, but Aang dropped to his knees and screamed for them to stop. His voice went unheeded as Avatars past pooled their collective knowledge of many horrible punishments. Finally one was decided upon: an eye for an eye.
"Katara."
Aang's voice was not his own, but instead was the voice of many, blurred into a cacophony of angry voices, sounding demonic and evil. It was deep and cruel, voicing the hurt that lay in Aang's heart.
"Your fate has been decided. You have broken my hearts, so you shall give me yours. A heart for a heart."
The Avatar raised a clawed hand, outstretched towards Katara. At firest she cringed, then began to scream as she felt her chest crackle and pop. Her ribcage was shattered and ripped outward. A spray of blood. The sound of tearing flesh. Silence. A slowly dwindling throbbing sound. The wind stopped and all was quiet from outside of the room. Azula threw open the doors, which now opened easily. Aang stood there, amidst rubble and blood. His robed were stained and his fingertips dripped with it. Azula approached cautiously, waiting until she was sure he was calm to come any closer. His tattoos were blue, but not glowing. His eyes were grey once more. He had tears streaming down his face. Azula stepped forward and her eyes widened as she noticed the scene. Zuko was dead, partially buried underneath a fallen section of wall. He had an immense burn on his chest and he was bleeding from many places where the bricks had cut his when they fell. She then looked at the bed, where a large spray of blood covered everything. The carnage was sickening and the smell of iron was overwhelming. Azula focused her attentions on the man who stood in the middle of the chaos, shuddering as he silently cried. She slowly moved closer to him, then noticed that his hand was covered in blood. It was also holding a throbbing, beating heart. Azula had never seen anything such as this before. It was frightening. Aang dropped the mass of muscle clenched in his hand and fell to his knees. Azula swept closer to him and held him, kneeling on the floor with him and holding him, his arms still limp at his sides. He cried into her robes, still feeling that terrible numbness. Katara had broken his heart, so the Avatar Spirit had torn out hers. He looked at the waterbender, still twitching on the bed. He felt a curious feeling move through him… joy? Why was he feeling joy? It must have been the beautiful firebender that was holding him. Then he remembered, he was Aang, the Avatar. He loved the woman in front of him, holding him and slowly rocking with him.
The take-over of the Fire Nation Capital was quick and easy. Azula had the best claim on the throne besides Iroh, and she held the avatar's support and affection. She vowed to take up the work that needed to be done since the war's end, saying that she would take up whatever slack Zuko had left behind. There were no bodies at Zuko's or Katara's funerals. There was simply a great pyre built to honor them, even though word of their scandal had reached many ears throughout the world. The story went that Zuko had attacked Aang and provoked the avatar State. What happened afterward was a mistake. Azula offered her official pardon and he was once again free to visit the Fire Nation whenever he wanted. He was also crowned Fire Lord, as Azula was Fire Lady. Their marriage took place three months after the brutal deaths of the adulterers. Aang had a difficult time explaining to the Gaang what had happened. He apologized to Sokka, who simply ignored his words and left the next day. Toph sensed Aang's truthfulness, but was still unhappy.
The Gaang disbanded, returning to whatever nations they came from, needed time to think on what had happened. Sokka soon started a campaign against Aang and the Fire Nations, saying he was choosing favorites. Aang was forced to go out and try and make peace, but Sokka would have none of it. He was struck down by Aang in the Battle of the Serpents Pass, where he and Aang met and dueled to the death while their opposing navies fought each other. Sokka was a good warrior, but without bending he was most grievously outmatched. Toph then opposed Aang, rousing the rest of the Gaang and starting an even larger rebellion. Aang had been worn down by the deaths of his friends, but before he flew out to Ba Sing Se, Azula gave Aang a night to remember, reaffirming their love and the love that would allow Aang to overcome his enemies. He personally tore down the wall of Ba Sing Se and his armies burned the rebellion to the ground. He personally sought out his old friends and one by one and destroyed them in an immense battle later known as the Friendly War. It was sadly downplayed, as the death toll had reached into the thousands.
Aang and Azula lived out the rest of their lives in peace and comfort. No one else dared rise to challenge the Avatar, nor his love of Azula. Aang wished his friends could have lived, and deep down he still felt immense guilt and pain, but then he held the woman of his affections in his arms and the guilt, the sadness and the sorrow all melted away. Guru Pathik's warning soon lay forgotten in the depths of Aang's mind, right next to the memories of his closest and dearest friends.
Aang entered a large room, a room that held haunted memories for him. Memories of blood, violence and a broken heart. The room of the Fire Lord. He straggled towards the bed, covered in the grime of war and travel. He was tired after a hard month's effort and several days of travel on top of that. He wanted nothing more than to sink into the comfort of the king sized mattress that was covered in a sea of red silk. Instead he grabbed his lounge robes and went off to the bathroom. He bathed and upon his return, he found Azula waiting for him. She was happy to see him, waiting in one of her rather generous outfits. It showed off her beautiful skin and her pale complexion that most associated with royalty.
"Welcome back, Avatar. I've been a very bad Fire Lady while you were away. You just might have to take away my bending. Unless, of course there is something else I can do for you… anything?"
Her voice was lathered in honey and seduction, and she positively purred the last word. Aang felt instantly gratified for his hours of hard fighting in several battles. He fell forward into Azula's embrace and they began to kiss, burning off what energy they had left at the end of the day. Aang felt his sorrows and his sluggishness fade as he held Azula in his arms. Azula loved him forevermore, vowing to never break Aang's heart as she was well aware of the severe consequences that would befall her own.