Disclaimer: I don't Naruto. If I did then NaruHina would be canon and what happens to Sasuke in my story would come true.
Killing in the Name
Sitting on what appeared to be a throne, Itachi waited for his brother. When Sasuke enter the hideout, he walked towards the murderer of their clan and the focus of his life. "Tell me Sasuke" Itachi asked "What do you see…with your Sharingan?" Sasuke didn't seem to be bothered by the question. He continued to move towards Itachi "What do I see, Itachi?" he queried "with the power I've gained, I see one thing, and its crystal clear."
He stopped in front the throne. Looking up at Itachi, while Itachi looked down at him, both their Sharingan eyes meet. "I see you dead."
In a flash Itachi vanished from the throne and swung a kunai at Sasuke. The younger Uchiha, ducked, pulled out, and swung a kunai of his own. They meet with a resounding clash of metal. Neither had any type of emotion on their face as they brought the kunai up. Suddenly Itachi collapsed into a puddle of water. 'Mizu-bunshin, huh?' Sasuke thought.
He dodged to the right as Itachi brought his sword down were he had been. "So were going to fight with kenjutsu? Without even telling me? That's low even for you brother" Sasuke said as he unsheathed Kusanagi. "So you took the legendary Kusanagi from Orochimaru?" Itachi said flatly. In was a statement, not a question.
"Yes, I did. Just so I could kill you with it, Itachi." Sasuke and Itachi began to circle each other, readying the instruments of death they each held. Sasuke struck first. He brought his blade down to perform a Helmbreaker, while Itachi swung up to block. When the cold metal meet, Sasuke swung Kusanagi down and horizontally across Itachi's chest.
He disappeared in a puff of smoke. 'Now a kage-bunshin? What are you up Itachi?' Sensing a chakra signature behind him, Sasuke managed to block the other sword just in time. "You have gotten much stronger, Sasuke. It looks like you hated me enough to become strong." Itachi taunted. Sasuke would not fall for that this though. He jumped away and rebounded of a wall, shooting straight at Itachi.
For his part, Itachi was actually surprised for a moment. That moment was all Sasuke needed to get an attack in. He sliced into Itachi's leg. This forced Itachi back and forced him to drop his sword. Sasuke landed on the ground and turned to face the older Uchiha. "Looks like you can't clash steel with me any more brother" he paused "why don't we continue this with taijutsu?"
Itachi looked over at Sasuke. "And how do you propose we do that, foolish little brother? My leg is wounded." Sasuke stared at the object of his hatred. "Come on Itachi, you must have copied so medical jutsu somewhere along the line. So why don't you cut the crap and heal yourself already?" Itachi chuckled darkly. "I suppose I can't put anything past you, now can I Sasuke?" he waited for a response. "Very well," when he got no response "I will heal myself now."
With a glowing green hand, Itachi ran it over his bleeding leg. It stopped bleeding and then close. When he was finished, he stood up and dropped into a taijutsu stance that Sasuke had never seen before. "This Sasuke, is the taijutsu style that I used to defeat our father before I killed him."
While not letting it show, Sasuke was seething inside 'I am going to enjoy this even more than before.'
Again it was Sasuke who started off first. He charged Itachi with his fist pulled back and punched at said brothers gut only to have him grab it and perform a reversal. Sasuke was being throw over his brothers head. 'Perfect' Sasuke thought. In the middle of the reversal, Itachi felt movement behind him. It was a kage-bunshin of Sasuke. In his current position, Itachi would not have been able to block or evade. This left one option.
He released Sasuke and back-flipped out of the way, expecting the clone to hit Sasuke. Instead, the clone opened its hands. Sasuke grabbed the clone's open hands and swung around in mid air. The clone and Sasuke released each other, which resulted in the young Uchiha being flung at Itachi. He twisted and extended his leg in flight so that his leg impacted Itachi in the stomach when he hit. Not expecting such moves from his brother, Itachi took the full blow from the kick.
Knocking him backwards and the breath from his lungs, Itachi dropped to one knee. Sasuke walked over to him and kicked Itachi in the side. "Get up Itachi. I know you can do better than this" Sasuke growled. He would not be denied the pleasure of ending the life of the man who ruined his.
Slowly.
Itachi got back up and stared into Sasuke's Sharingan. "Where did you learn to perform moves such as that?" he asked "From Naruto." The answer was not what Itachi expected. 'The Kyuubi jinchuriki?' "Yes, I know. People wouldn't expect to learn anything from that dobe. But people ignore the obvious benefits from seemingly random attacks."
"I say its time to end this Sasuke. Show me your full power. We will go all out now." Itachi looked into Sasuke's eyes and used Tsukiyomi. Nothing happened. 'How is this possible?' Itachi thought to himself. Sasuke's laughter brought him out of contemplation. "I wondered what kind of side-effects came with absorbing Orochimaru."
Itachi knew that the Tsukiyomi was now useless. Sasuke looked over him and smirked. He proceeded to run through a series of seals, ending on Tiger and shouted "Katon: Goukakyuu no Jutsu." The massive fireball raced towards Itachi, who had just moments to dodge.
Itachi got up and ran through seals of his own and shouted "Katon: Karyuu Endan" The fire dragon raced forward, aiming to kill Sasuke. He jumped out of the way and did three seals, then gripped his right hand with his left. Suddenly, lightning began to crackle around Sasuke's hand and in a burst of speed, charged Itachi.
Trying to control the Karyuu Endan took a bit of Itachi's concentration. Enough that he didn't notice his brother create and charge a Chidori. He noticed when Sasuke appeared in front of his and rammed a Chidori into his chest.
The dragon dissipated as Itachi fell to the floor, clutching his chest. Blood ran freely out of the wound and he knew that Sasuke had won. "So" Itachi started "It seems that you are indeed stronger than I am. It's good to know where I stood on the scale." He coughed up blood and looked right into Sasuke's eyes "But I have the last laugh, foolish little brother. While you have been chasing your dream to kill me, what cough coughhave you done about your other goal. Have you begun to restart the Uchiha clan? I cough thought not.
Sasuke did not like where this was headed. "Why do you care? You are almost dead anyway" he asked. Itachi chuckled again, with absolutely no mirth "Because Sasuke, since you abandoned the village, they will most likely kill you. And if you go to another village they will either kill you on sight or turn you over to Konoha for punishment."
"How do you know? Another village would jump at the chance to have the Sharingan. Why would they kill me?" Sasuke asked, really not liking where this was going.
"Because brother" he gasped for another breath "you have betrayed not one but two villages. You gasp have been labeled a traitor to all. You have no where to go. Good Bye Sasuke. I'll see you soon." And with that Uchiha Itachi, murderer of the Uchiha Clan, died.
Sasuke stood there absorbing what his brother had told him. 'No. I can't be true.' Sasuke couldn't comprehend the fact that he was essentially a dead man walking. "Raikiri!" He heard the voice and recognized it immediately. 'Kakashi? What's going o…' his thoughts came to an abrupt end. Sasuke could feel his life leaving him, and with the last of his strength, he turned around to see who had killed him.
The last images his eyes saw was Kakashi standing over him, with Naruto and Sakura directly behind him. In the back were several people he didn't recognize. As light faded from his eyes, he looked at the few people he had ever cared about since the massacre.
And with his last breath Uchiha Sasuke, the last Uchiha alive, spoke the two words that meant the most "I'm sorry." His heart stopped beating and the Uchiha Clan was dead.
Forever.
Thanks for reading. I hope Sasuke's death was good enough for all those who wanted it so much.