My name is Sasuke Uchiha.

Tonraq, Senna, and Korra, thank you for all you've done, but I must leave. I am writing this because Katara suggested I leave something behind. After some reflection, I realized you deserve the same explanation I gave her. So, I suppose I should begin with some crucial information.

I am not from the Four Nations or even your world. I come from another world in which you can find the Elemental Countries. A collection of various lands. For example, Land of Rain and Land of Earth. These names don't indicate a certain group you'd find there.

It does usually correlate to the Chakra Nature that is most common though. I was born to the Land of Fire in the Village Hidden in the Leaves. It was a village which has civilians and Shinobi. Shinobi are like military and mercenaries rolled into one.

I was born and named Sasuke after the Third Hokage's father. The Hokage is a position that can be passed down or elected to. My last name, Uchiha, was used by everyone who had my Blood Line Limit. A special ability not every ninja had, but it gives a clan status and power.

My close family was my big brother Itachi, my mother Mikoto, and father Fugaku. My brother was a prodigy in every sense of the word. To give you a frame of reference, a Shinobi is ranked by strength. You start as a student and graduate around 11-12 years old.

You're then a Genin put under the mentorship of a Jonin until you become a Chunin. Chunin can lead experienced Shinobi on missions. Finally, Jonin which is the highest rank. Even though the forces were wakened due to a war, his advancement to higher ranks was fast.

He graduated from the academy at 7, passed the Chunin Exams by himself at 10, entered Anbu at 11, and led the organization at 13. I looked up to and loved him. I always wanted to play with or learn something new from him. Reminds me of a certain Avatar when we were younger.

Anyways, my mom was kind yet strict. She always said play could wait as Itachi had homework, or important Shinobi duties. Even so, Itachi made time for me no matter how annoying I could be. It might be surprising, given how I've been, but I was an excitable kid. Very eager.

As for my father, he was strict and distant. I wanted his approval, but he always compared me to Itachi. My achievements couldn't measure up to my big brother. I was always behind where he was at my age until things were set in motion. My clan was going to rebel against the village.

There's a lot of history you don't need to know. Just understand that the Uchiha Clan felt as though they were being pushed further from their prominence in the village. Itachi was caught between his loyalty to village and clan. In the end, something had to be done.

Either rebellion or Itachi could slaughter everyone. He chose to slaughter the clan, but he couldn't kill me. His plan was to let me live, have me kill him, and be a hero. He made me an avenger and unknowingly instilled the Curse of Hatred within me.

Itachi left the village and joined an organization of S ranked Missing-nin. He did this to act as a double agent for the third, but I never learned about it until much later. From that day onward, I was cold and distant; however, someone made a bond with me. My rival, Naruto Uzumaki.

I thought he was annoying and a loser. He competed with me for everything, but I always won. Things went on like that until I graduated. At this point, I had annoying fan girls that I wouldn't give the time of day. Unfortunately, Sakura, who was one of them, and Naruto were on my team.

Our Sensei was Kakashi Hatake. He was one of the strongest Jonin of the Hidden Leaf Village. He found us annoying, taught us something important, and we undertook missions together. In a way, I was starting to open myself to them and the village's way of thinking.

Then, the Chunin Exams came around. During the second test, we were met by a Sanin. That was a tittle given to three exceptional Shinobi during the second war. This one had become a missing nin, was an ex-member of the Akatsuki, and attacked his former home.

I fought him, but he was too strong. When he left, I received what's known as a Curse Mark. It granted power but amplified my hatred. After the Chunin Exam, I met my brother again. He was after Naruto for one of nine beast he held. Think of them as dark, powerful spirits.

Once again, my brother reminded me of my hatred before putting me in a coma. The only one who could help me was Lady Tsunade. She was another Sanin and renowned healer. Naruto and Jiraiya, the last of the Sanin, brought her back to the village.

It wasn't long after that I began to take notice of Naruto's increasing strength. We fought on the roof of the hospital but were stopped by our Sensei. After seeing my rival's strength, my hatred increased. Soon, Orochimaru's henchmen came for me with the promise of power.

I left with them prompting the village to mount a rescue. Eventually, I faced Naruto, managed a win, and escaped into Orochimaru's clutches. He trained me, but I never gave into his request to kill. At the time, the only one I wanted dead was Itachi.

After three years, Naruto and Sakura found me with two other Shinobi. I showed them my strength and prepared to finish them before Orochimaru took me away. Now, Orochimaru wanted my body. I'd cease to be, but I was fine with that if Itachi died.

Then, I came to realize Orochimaru was weaker than I. I killed the snake before leaving and recruiting three others from Orochimaru's compounds. I used them to help me find Itachi. Killed one Akatsuki member before I found him. The recruits held off his partner, and we fought.

As I said, Itachi never intended on winning, but he was certainly capable of it. At the time, he was plagued by a terrible sickness and going blind. Before he died, he freed me of the Curse Mark, but the Curse of Hatred was a different story. I learned the truth about Itachi.

He loved the Leaf Village, but my hatred wanted it to fall. I took my three new teammates and moved to attack the Leaf; however, we ended being pulled into the Akatsuki. We attacked and thought we captured someone who held the eight tails.

We eventually ended up invading a summit meant to discuss the Akatsuki and I. I abandoned my team and killed one of the elders of the Leaf. I then attempted to kill Sakura and Kakashi, but Naruto stopped. Eventually, I got drawn into the Fourth Great War of my world.

It was between the Akatsuki and the five major Shinobi Villages. While on the battlefield, I saw the reanimated corpse of my brother. I chased after him and helped stop the reanimation. Before he vanished, Itachi apologized. I then brought Orochimaru back.

Once he saw how strong I was, the snake was willing to do what I asked. So, I told him to reanimate the previous Hokage. It was through my interactions with them that I learned what it means to be a Shinobi and decided to join the war.

I wanted to prevent Itachi and the village from coming to mean nothing. When I appeared, I declared that I would become Hokage. A dream held by my rival, but I would become a different Hokage. I'd use my strength to force everyone's hatred onto myself.

I would keep the other villages in line from the shadows. It was a long and hard-fought battle. Many things happened, but the Allied Shinobi Force won. During the time I was on the battlefield, everyone had been trapped. Naruto and I had the power to free them.

Weather that's together or through one of us killing the other. The later was my intention. I knocked out Sakura and left her with Kakashi as I egged Naruto to follow me for our final fight. In the end, we tied, but Naruto finally got through to me.

He impressed the importance of our bond and shown light into the darkness I'd walked into. I finally returned home, was imprisoned for some time, and only freed thanks to Naruto and Kakashi vouching for me. In our battle, Naruto and I lost our arms.

Replacements were available, but I choose not to receive it. I would only have one arm as a reminder. Shortly after my release, I decided to leave the village and wander the world. To understand how I felt about it. Naruto gave me my old head band.

The one I always wear in this new world. The moment I took the headband, I was sucked into a white portal. The last thing I saw of my world were the shocked faces of my teammates. I ended up in a white void where I was confronted by the Sage of Six Paths.

He was the father of Ninshu which gave way to Ninjutsu. He told me someone, he didn't know who, crossed the barrier into our afterlife. This person left with countless dead Shinobi. In doing so, the perpetrator had bound them to this world.

To counteract this, I was to be bound to the world myself and become its Sage. I protested because I was not the right person for this job. My protest didn't matter. I was suddenly standing before Raava. A powerful spirit from your world. I argued with her, but nothing could be done.

I was already bound to this world. She was to be sealed within me which would grant me the ability to unlock Chakra in the people of this world and grant them Blood Line Limits. She also warned me of something called the Harmonic Convergence.

It's an event that will happen in your world. The next thing I know I'm in an icy landscape, my Chakra is thrown into whack with Raava inside me, and I'm three years old. I no longer had my previously acquired skills, speed, or strength.

The only thing for miles was the Southern Water Tribe in the distance. In the end, I tried to make it to the village only to collapse near it. I would have died if not for you Tonraq. You brought me into your home. I was unsure about everything upon waking.

When Senna asked who I was, I had to lie. I told you guys my name was just Sasuke, our ship had crashed, my parents had died, and acted as though I had selective amnesia. You believed me, and you even searched for them. After you brought me into your family, I wanted to leave.

I knew I'd be a danger to you, but I was a kid with no family, no identification, and not even of this world. I had no choice but to stay. Senna, you felt sorry for me. At the time, you hugged, and continue to hug. They were warm like my previous mother's.

I felt genuine love, but I never deserved it. Still don't. I didn't deserve to become a Southern Tribesmen, part of your family, or older brother to the Avatar. I didn't deserve Korra acting like I did to Itachi. I remember how much it hurt her when I'd ignore her.

It took you two talking to me about it before I started putting on an act as not to hurt Korra or cause undue worry. That's what it started as, but soon I fell into this life. Hunting with and learning from Tonraq, helping Senna cook, and being a big brother to Korra.

It all became genuine, and I felt happy. Every year, the thought of why I was brought to this world was put behind me. I still trained, in secret, and I'd say I'm about as strong now as I was when I left the Leaf village. Probably due to this peace your world has.

I guess I became as much of a kid as I could. When I started to hunt alone, I'd use my skills to increase the haul. I'm getting slightly off topic. This year hit me hard since Korra's now 17. The Sage said that sometime during the Avatar's 17th year, Shinobi would start impacting the world.

That means I can't ignore this any longer. I don't belong… can't belong. I'm not a good person. That said, writing this out makes me realize I need to tell you three the truth in person like I did Katara. Maybe that was the wise woman's intention. I don't know…

Water Tribe Home

Sasuke looked much like he had after the war; however, he had both his arms, no Rinnegan or power from the Sage of Six Paths, and his spiky, black hair had been kept to its length from before he left to join Orochimaru. His Konoha head band was tied around his forehead.

Sasuke wore a dark blue, log sleeved shirt underneath a light blue Water Tribe outfit with brown boots. On the back he had the Water Tribe Symbol and Uchiha Clan Symbol side by side. Until today, Senna, Tonraq, and Korra didn't know why he'd requested both symbols on his back.

Tonraq was a muscular, tall man with long black hair and beard while Senna was a bit shorter with her black hair in twin tails at her sides. Korra was athletically built with a height in between her two parents and her black hair in a tri-pony tail.

The family were stunned after hearing what Sasuke had to say. It was a lot to process, and the Uchiha, by no means, included everything because he didn't feel that was important. Yeah, he was the reincarnation of Indra, but he couldn't talk to the guy or Madara.

As far as he was concerned, that was good. What wasn't good was the fact that his adopted family seemed to be processing things poorly. Korra was saddened, Tonraq seemed disapproving, and Senna was worried.

"I should have just left without saying anything." Sasuke thought.

Raava spoke to him from within. "Sasuke, you don't know that their emotions are directed negatively towards you."

"Well, it all seems clear to me Raava." Sasuke ran from the house. "They don't need me to make them feel any worse."

Korra ran to the open doorway. "Sasuke, wait!" he continued running, showing the speed of a Shinobi, and ended up jumping over the wall. "This is really bad." She turned to her parents. "We have to go after him."

Tonraq sighed. "Are we sure that's the best course of action?"

"Dad/Tonraq!" Korra/Senna shouted in disbelief.

"Look, I'm just saying we should take the time to think over everything Sasuke told us." Tonraq stated. "Sasuke's still my son, but…"

Korra was already out the door and running to get Naga.

Senna looked at him. "Do you mean that?"

"Senna, all three of us were taken off guard by what he told us." Tonraq stated. "I thought this was a meeting to tell us he'd proposed to some secret girlfriend of his. Not that he was from some other world."

Senna sighed. "I will admit that it does sound insane, but it also explains a lot about him. Remember how distant he used to be? Not to mention how selective his amnesia seemed. Finally, his speed is far greater than the few times he's trained with you."

Tonraq nodded before taking a deep breath. "I'll take this time to process what our son has said while Korra has her talk with him. I honestly don't want to say the wrong thing here Senna." He crossed his arms and sighed. "I suppose not saying anything was wrong, huh?"

"Well, we're all guilty of that." Senna stated. "I think what's important is that we still love him, right? I absolutely do."

"I do to." Tonraq stated.

Senna grabbed his hand and smiled. "Then let's work through what he's told us and come up with the right words."

Tonraq gave his wife a small smile. "You are right dear." He then frowned. "Senna, so you think this is why the Red Lotus were after Sasuke as well as Korra? Our son is strong, but I never understood why they'd be after him."

Senna thought about it. She hadn't confronted the Red Lotus since she was no fighter, but her husband had told her about the encounter after he returned.

"It's possible." Senna stated. "The way Sasuke describes a Shinobi… Did any of the members you face seem odd?"

Tonraq crossed his arms. "No, they all performed like any Bender or Non-Bender we're used to. That said, the four Sokka, Zuko, Lin, Tenzin, and I faced were likely a small cell of the Red Lotus. Given what we've just found out, there could be Shinobi counted among their ranks."

Icy Cliff Overlooking the Ocean

Sasuke had ran to his usual cliff and looked out over the ocean. "Raava, why didn't you ever remind me of my mission? Why did you let me become attached to them?"

Raava replied. "Sasuke, I know you better than anyone after the years we've spent together. You were growing at a fine rate and deserved some peace. What I want to know is why you ran without getting an answer from your family?"

"You know why I ran."Sasuke thought.

"I do, but I want to hear you say it." Raava replied. "I want you to admit it to yourself."

Before he could say anything, he heard Naga behind him. The Shinobi stood to run off only for ice to ensnare his feet. He looked back and saw Korra lowering her arm. She was clearly angry and Sasuke didn't blame her.

"Why did you run?" Korra asked.

Sasuke was shocked. "What?"

Korra approached him and only removed the ice from his feet once she was close. "You heard me big brother. Why did you run away before giving us the chance to speak our minds? Considering you just told the truth; I want nothing but the truth now."

"You want the truth Korra?" Sasuke walked closer to the edge with his hands up. "The truth is, I was terrified of facing you three. If the dobe could see me now, he'd laugh. The great Sasuke Uchiha, after the night of the massacre, was afraid once again.

I was terrified you'd all cast me out anyways. At least this way I could pretend to still have a family. To me, after 15 years with you all, it would be better to pretend having you than to lose you in that way. I…"

He stopped as Korra wrapped her arms around him. "You haven't lost me at least." Sasuke looked back at her in shock. "I'm your little sister, and you're my big brother. Your past doesn't change that because you are a good person."

Sasuke broke away from her. "I'm not a good person Korra. I'm terrible and do not deserve to be the brother of the Avatar. I don't deserve good parents or a great sister after everything I've done in my past life. The person who should be here is Naruto.

He's the one the Sage should have picked, the one who should live in this peaceful world, and the guy who would be a better brother than I ever could be. Sadly, this world is stuck with me because he's important to the previous world.

I'm not because the Sage said it himself. Itachi could do my job, and he will. My big brother was never truly a bad person. Now, thanks to whatever is causing this whole situation, he gets the chance to live again. I know Naruto will ensure he gets to be free like I was."

"You're not the one who gets to make that choice." Korra slapped Sasuke. "You don't get to decide or say who my brother should be. I say you're the brother I deserve, you're the guy for the mission of this Sage person, and you deserve to be in this world.

If you think for a second that I'm going to let you run, you got another thing coming. I will track you to the ends of the earth, as many times as it takes, and slap you across the face until you get the point. Sasuke Uchiha, I once asked you if you'd always be there for me, and you said?"

Sasuke's eyes went wide before he looked away from her as he remembered that day. "I promised I'd always be there for you before pressing two fingers to your forehead. I honestly believe and believed that the Avatar needs a strong support system."

"If there's one thing dad taught you, it's that a man honors his word." Korra crossed her arms. "No matter what you may have done, you've changed. No matter what you say, I think you're a great person."

Sasuke looked at her. "But my past…"

"What about your past?" Korra shook her head. "It doesn't matter to me. You matter to me Sasuke." She hugged him once more as her voice shook and tears threatened to spill from her eyes. "Please don't run away."

Sasuke chuckled weakly. "I also promised I'd never be the reason you cried." He hugged her back and let out a deep breath. "I'm sorry Korra."

"Just never consider leaving me again Sasuke, and I'll forgive you." Korra stated.

Sasuke nodded. "Korra, I remake my promise to you now. As your brother, I will never leave you no matter what the future has in store for me."

They pulled apart from each other and Sasuke tapped her forehead like Itachi had done him.

Korra rubbed her head a little frustrated. "You big jerk. First, you make me go through a range of emotions. Then, you end up tapping my forehead."

Sasuke smirked. "It stopped you from crying, didn't it Korra?"

Korra smiled glad to see that Sasuke was starting to act like himself. "We need to return to mom and dad." She started walking over to Naga. "If they're against you, I got your back."

Sasuke was still uncertain about much, but he was at least certain he had the love of his adopted sister. To him, that was a victory after years of uncertainty. With her having his back, he felt confident returning home. He joined her only for Naga to lick him.

Sasuke rubbed his face as Korra laughed. "See, Naga would have missed you, and she doesn't care about your past."

Sasuke was disgruntled before smiling and petting the big animal. He and Korra got on the polar bear dog before starting the trek back to the White Lotus Compound.

Home

Korra and Sasuke dismounted Naga and walked up to their home only for the doors to be thrown open as Senna ran over to them.

She hugged Sasuke while Tonraq watched from the doorway. "Sasuke, what were you thinking?" She pulled back. "Haven't I shown you that I love you? A mother's love is not conditional. No matter what you may have done, you are my son."

"Se-mom." Sasuke stated. "I'm sorry. I was terrified of what you'd all think of me, but Korra made me see how stupid I was."

"Here I thought you were the smart one." Tonraq stepped outside. "Sasuke, we don't hold anything against you for your past. Your reasons don't justify what you did, but I think we all understand why you did them. Clearly, you regret your actions."

"More than you know dad." Sasuke stated. "I think that's part of the reason I began acting better until it wasn't an act. I didn't want to be who I was, but without my world, I had to ensure I'd change. It's thanks to you three that I won't fall down the same path."

Tonraq nodded before bringing his son in for a hug. He then added his daughter and wife to make sure that Sasuke knew they loved him.

Inside: Living Room, Later…

With everything calming down, the family of four sat down to further discuss things.

"So, you were sent here to stop Shinobi from your world?" Tonraq asked.

Sasuke nodded. "As I said, something or someone in this world breached into mine's afterlife. The Sage only told me they'd really start making moves around the time the Avatar turned 17."

"So, you contain some powerful light spirt which is bound to you?" Korra asked. "This spirit pretty much makes you a carrier of Blood Line Limits which are powerful abilities you can pass onto others. Not only that, but you can do the same with Chakra as well."

"Well, Raava has allowed me to call her a Spirit, but she doesn't identify herself as such. She's told me there's a lot to explain, but she wants to wait until we draw closer to Harmonic Convergence." Sasuke replied.

Senna nodded. "So, you've been training to fight these Shinobi?"

"More or less." Sasuke sighed. "I'll be honest, I haven't been as into my training as I was in my previous world. I don't have hatred to fuel me, there was my obligations to the Southern Water Tribe, and the peace of this world.

I haven't grown as strong as I should, but maybe giving me something to fight for is what Raava has been trying to achieve. Naruto once met a Shinobi who opposed us on a mission. That Shinobi taught him the importance of having people precious for you to protect."

"Well, the answer is obvious." Korra smiled. "You and I are going to start training together." She punched the palm of her hand. "You're not alone because it's my job to bring balance, right? If the dead walk a world that isn't theirs, shouldn't it be my responsibility to stop them to?"

Sasuke was surprised. "You're taking the news of my strength better than I thought you would?"

"Hey, we don't know if you're stronger than me." Korra gave a small smile. "If you are, you'd be one of the people I'd be happy with being better than I. As I said, it should be my job, and I don't want to see anything bad happen to you.

Since you are stronger than the average warrior you were pretending to be, I don't have to worry about you as much." She nodded. "If anyone's going to be mad or disappointed, it'll be Tenzin and Soren."

Sasuke nodded as the girl came to mind. "That's right."

Korra shook her head. "Well, never mind that for now. We can give you some time as I finish up Fire Bending." She smirked. "I think I've almost got it mastered which means Tenzin should move here shortly after. You can tell him then."

Tonraq shook his head. "To think, we'd end up with two children who were given great destinies."

Senna smiled. "We're both so proud of you two."