Reviving the Uchiha Clan: Starting with a Legacy of Many Descendants

Inside a private room at the Konoha Hospital.

Sasuke lay on the bed, drenched in sweat, his eyes tightly shut as he murmured in distress. He was caught in a terrifying and bloody recurring nightmare.

"Father, Mother! No... Brother! Stop! Stop it!" he cried out.

With a sickening slash, his parents fell to Itachi's blade, blood spraying everywhere. The same horrific scene played out over and over, thousands of times.

Sasuke was on the brink of madness, clutching his head and sobbing uncontrollably.

Suddenly, he collapsed to the ground, trembling violently, drooling as he spoke through choked sobs, "Why, brother, why... why did you do this? What do you gain from killing our clan?"

Itachi's cold voice responded, "To measure my capacity..."

"Measure... capacity? For that, you killed everyone?" Sasuke questioned in disbelief.

"You don't understand. It is crucial..." Itachi replied icily.

"Don't joke around!" Sasuke's despair turned to rage. He threw his small fists at Itachi, who effortlessly knocked him down with a single blow to the stomach.

"Ugh!" Sasuke clutched his stomach, kneeling in pain. The chilling killing intent from his once beloved brother filled him with terror.

"So... so frightening!" Sasuke's survival instinct kicked in. Despite being only seven, he knew he had to escape. The murderous intent from Itachi clouded his mind, every cell in his body screaming one word: "Run!"

"Don't kill me! Don't kill me!!" Sasuke sprinted out of the room, running aimlessly under the blood-red moon. He didn't want to die.

But as he ran, despair set in once more. At the end of the road stood Itachi, waiting.

Seeing no way out, Sasuke shook his head frantically, denying the reality before him. "Brother, no! I don't believe it. You're not my brother! My brother loves me; he wouldn't do this!"

Itachi's expression remained unchanged, his voice as cold as ever, "It was all an act. I pretended to be the brother you wanted to measure your potential. I won't kill you now. You will be the measure of my capacity. I believe you have the potential to awaken the Mangekyō Sharingan, but it requires you to witness the death of your closest friend or family..."

Sasuke's eyes widened in shock, "That... that's impossible!"

"Thanks to Shisui, I awakened this invincible eye technique... the Mangekyō Sharingan," Itachi continued.

Sasuke gasped, "Shisui-senpai's disappearance... was it you, brother?!"

Itachi didn't elaborate. "The Naka Shrine in the Uchiha compound, beneath the seventh tatami mat from the right, holds our clan's secrets. It details why we exist and the true secrets of the Sharingan. If you can awaken it, there will be three of us with Mangekyō Sharingan. That's why I let you live. Currently, you are too weak to be worth killing."

"My foolish little brother, to kill me, you must live in hatred and aversion. Survive pathetically, and when you have eyes like mine, come before me. I hope by then, you won't be as pitiful as you are now..."

With that, Itachi's Mangekyō Sharingan flared again.

At that moment, Sasuke awoke with a start in his hospital bed. He panted heavily, the pain in his arm grounding him in reality.

Everything in his nightmare was true. The massacre, the deaths of his family, and his brother's betrayal were all real.

His clan was annihilated.

His family was dead.

His brother was gone.

It wasn't an illusion; it was all true.

Sasuke, still in shock, stumbled out of the hospital room, heading towards the Uchiha compound to see it for himself.

At the corner, he overheard two young nurses talking about the Uchiha clan.

"Hasn't Sasuke woken up yet? Poor kid..." one nurse said.

"Yeah, who would have thought something like this would happen to such a prestigious clan..." the other replied.

"After the massacre, Konoha lost nearly half of its strongest and most handsome men. 555... I'm so upset. My dream was to marry into the Uchiha clan, and now they're all gone..." the first nurse lamented.

"Well, you still have a chance! I heard there's another Uchiha who's looking for a wife," the second nurse giggled.

Sasuke froze. Another Uchiha alive? Who?

He needed to know the name of this surviving clan member. Maybe he wasn't completely alone.

The nurses continued chatting.

"Looking for a wife? Really?" one asked.

"Yes, it's true. On my way to work this afternoon, I saw a lot of villagers talking about it at the bulletin board. If I hadn't been in a hurry, I would've stopped to read it," the other responded.

"Wait, the surviving Uchiha is named Xia Yu, right? I've heard he has quite the reputation. This scoundrel even went as far as publicly seeking wives. How shameless..." the first nurse said.

Sasuke's initial relief turned to anger. Xia Yu was known as the disgrace of the Uchiha clan, someone everyone despised. 

"Why is the other survivor him?!" Sasuke fumed. "No wonder he's pulling such a stunt. Any respectable Uchiha wouldn't be doing this at a time like this!"

"That disgrace! I need to teach him a lesson. If he continues, the Uchiha name will be completely tarnished!" Sasuke thought. 

Despite his young age, Sasuke held a deep sense of pride in his clan. As the son of the Uchiha clan head, he couldn't tolerate Xia Yu's disgraceful behavior.

He bolted out of the hospital, racing towards the Uchiha compound, a kunai in hand, ready to confront Xia Yu.

"I'll handle Xia Yu myself. Even Itachi didn't consider him an Uchiha. I'll deal with him. They're both stains on our clan. They're the people I hate most!" Sasuke thought furiously.

He arrived at the Uchiha compound's gate.

"Xia Yu, I'm going to kill you!" he shouted.

But then, he froze.

The scene before him was completely unexpected.

He had expected desolation.

Instead, it was bustling with people, even livelier than before the massacre.

"What... what is going on here?" he wondered in shock.

...