Uchiha Compound

Hiruzen Sarutobi took a long draw from his pipe and pushed open the door, his heart heavy, his face clouded with grief.

"The Uchiha Clan Massacre was a failure on my part as Hokage. If only I'd noticed something was wrong with Itachi sooner, or spotted the strange activity in the Uchiha Compound earlier, this tragedy might never have happened. I failed you, Mufeng, Sasuke..."

His words were heartfelt as he began recounting the Uchiha Clan's many contributions over the years. What an award-worthy performance. If I hadn't watched Naruto, I might've fallen for it.

"No, Lord Hokage, this was all Itachi Uchiha's fault! I was too weak. I could only watch as he killed them. If I'd been stronger, maybe they would've survived."

Mufeng Uchiha played along with Hiruzen Sarutobi, clenching his fists and pounding the bed in anger. Then Hiruzen suddenly asked,

"Mufeng, I know it'll be painful to recall what happened that night, but we need to capture Itachi Uchiha. Please tell me everything you can about what happened."

There it was—the fox's tail. He wanted to find out whether Itachi had revealed any secrets to the two of us survivors.

Mufeng Uchiha acted as if he were in great pain, clutching his chest. He said only that he'd passed out after Itachi Uchiha used his ocular genjutsu on him, and that he knew nothing after that.

Having achieved his aim, Hiruzen Sarutobi offered a few words of comfort and left. During their conversation, Mufeng Uchiha had also learned that Sasuke Uchiha had already returned to the compound.

Not long after Hiruzen Sarutobi left the hospital room, Mufeng Uchiha slipped out too.

"Little one, you haven't recovered yet. You shouldn't be walking around."

"Let him go. After everything that's happened at home, he needs some time to calm down."

Following the familiar path he'd walked countless times before, Mufeng Uchiha hurried back to the compound. The first place he went was the loft where the Uchiha had stored their ninjutsu and records.

"Just as I thought. All these precious techniques and records have been taken, and everything they couldn't carry off has been burned or destroyed. No, I have to keep looking."

The Uchiha had survived from the Warring States period to the present, with nearly a thousand years of accumulated history. He refused to believe Root and Anbu had managed to loot every last thing.

"All that's left is a single copy of Uchiha Style Swordsmanship, left behind by Izuna Uchiha. It's been burned beyond recognition, too. Oh well, something's better than nothing. I'll see if I can combine it with Water Breathing to create a new sword style."

He wasn't just one person now—he was thousands upon thousands of Mufengs. With their astonishing intellect, he was confident they could create a sword style that surpassed Uchiha Style in no time.

"If there's only one sword manual left in the archive, they've probably looted everywhere else, too. But my house was the last crime scene. The Third and Danzo probably haven't had time to search it yet. I need to get back as soon as possible."

As soon as Mufeng Uchiha stepped into the courtyard, he saw Uchiha Sasuke furiously pummeling a wooden post. He was attacking it as if he wanted to hurt himself, and his hands and feet were already bleeding.

They were brothers, after all. He couldn't help warning him.

"If you don't want to spend the rest of your life in a wheelchair, stop right now. If you go after Itachi like this, all you'll do is give him your eyes."

"Don't say that man's name again! I'll kill him and avenge our clan. No one can stop me!"

As they spoke, Uchiha Sasuke, his reason gone, charged at Mufeng Uchiha like a madman.

Sasuke had completely lost control. It looked like he'd have to be taught a lesson.

Sasuke's wild punches looked like a child's tantrum to Mufeng Uchiha. He simply lifted a foot and planted it on Sasuke's chest, pinning him firmly to the ground.

"Calmed down yet, Sasuke? If you keep this up, forget revenge. Stay in the village and help the Uchiha Clan grow."

The moment Uchiha Sasuke regained his senses, he drew a shuriken and hurled it straight at Mufeng Uchiha's neck. Mufeng Uchiha tapped Sasuke's chest with his toes and sprang into the air.

The volley of more than a dozen shuriken only managed to tear a little fabric from Mufeng Uchiha's clothes.

"Fire Style: Great Fireball Technique!"

Uchiha Sasuke, still completely out of control, formed Hand Seals and spat out a Great Fireball about ten centimeters in diameter.

Mufeng Uchiha immediately activated his Sharingan. In midair, he stamped on a spinning shuriken to propel himself, forcibly changing direction and dodging the Great Fireball as he shot straight toward Uchiha Sasuke.

"Nice one, Sasuke! You're really going all out against your own big brother! I'll have to teach you a lesson so you remember who's boss."

Before Sasuke could react, Mufeng Uchiha hit him with a flying tackle, straddled him, and swung both arms in wide arcs, slapping him left and right across the face. He kept going until he ran out of strength, then lay down beside Uchiha Sasuke.

"Calmed down now, Sasuke?"

"Mm... I'm s-sorry."

"You can barely talk, so don't argue. Let's get you inside and treated first."

Before long, Uchiha Sasuke was sitting inside with bandages wrapped around his face, leaving only his eyes and mouth exposed. The culprit, Mufeng Uchiha, sat across from him, staring at the ninjutsu scrolls and money they'd salvaged from the floor and sighing repeatedly.

"They looted us way too thoroughly. They even took all of Pops's secret stash. If Mother hadn't hidden some emergency money, we'd really be penniless."

Aside from the two hundred thousand ryo Mikoto Uchiha had left behind, the only ninjutsu in the house were the Shadow Clone Technique, Phoenix Sage Fire Technique, and Majestic Destroyer Flame.

"Hmph, I don't need any of this. I can kill that man by myself."

"Hasutake, beat me first before you say that."

"I was just caught off guard! And call me big brother, you bastard, Mufeng!"

In his excitement, Uchiha Sasuke started to get up and challenge Mufeng Uchiha, but Mufeng pressed a hand against his shoulder and pushed him back down.

"If you go after Itachi now, you'll just get yourself killed. Train in Konoha until you're strong enough. After that, you can go avenge yourself on Itachi if you want."

He'd felt Mufeng's strength firsthand just now. Had Mufeng really undergone some kind of secret training?

Once he improved his own strength with Mufeng's training, surely someone as talented as him could surpass Mufeng in no time. Then he'd make Mufeng Uchiha call him big brother properly.

Mufeng Uchiha's thinking was simple: he needed to improve Uchiha Sasuke's strength. After all, even if they dealt with Itachi Uchiha, there were still threats like the Fourth Shinobi World War and the Otsutsuki invasion.

He wouldn't be enough to face all of them alone, so he needed to build up his strength early and prepare for the future.

He would seek even greater power. Only then could he fulfill every Mufeng's wish and stand at the very top of the world!

"I'll teach you a secret technique called Water Breathing. It'll greatly improve your physical abilities, and it's also a powerful sword style."

With that, Mufeng Uchiha gave Uchiha Sasuke a brief explanation of the Breathing Style used by Demon Slayer Mufeng.

In the courtyard, the two of them took a pair of swords from the house and began practicing Water Breathing. Drawing on the memories shared by Demon Slayer Mufeng, Mufeng Uchiha quickly entered a state of Total Concentration.

Beside him, Uchiha Sasuke copied his movements, still wondering whether any of this would actually work.

Could changing the way he breathed really make him stronger? Was Mufeng messing with him?

"Water Breathing, Total Concentration!"

Mufeng Uchiha gripped his sword in both hands and swung it at a boulder five meters across in the courtyard. The boulder split in two, the cut so smooth it had not the slightest unevenness.

"No. I'm Uchiha Sasuke, a genius. If Mufeng can do it, there's no reason I can't."

After seeing the power of Water Breathing, Uchiha Sasuke stopped doubting it and threw himself into training.

Through the long night, the two boys trained tirelessly in the quiet Uchiha Compound. In the shadows, the Root and Anbu ninja who'd been observing them each left, some of them heading off to report what they'd just witnessed to Lord Hokage and Danzo.