Itachi Uchiha's strength was undeniable. He had reached the threshold of Kage-level power at the mere age of thirteen. Capable of going toe-to-toe with Shisui and surviving ANBU pursuit, his skills had only grown sharper over the years. Among the elite combatants of the major shinobi villages, he was clearly a standout.
Sasuke, too, was no weakling. During the Chūnin Exams, he had already demonstrated Jōnin-level prowess. After undergoing trials in the Sound Village and Ryūchi Cave, he too had stepped into Kage-level territory.
Though there was a gap in their strength, it wasn't insurmountable.
Following a fierce initial clash, the brothers quickly disengaged. Itachi's fighting style was the epitome of the Uchiha: deadly elegance, like a dance atop a blade's edge. Sasuke's style, however, bore the subtle venom of Orochimaru and Kabuto, calm on the surface, hiding a killing intent underneath.
In the next instant, they hurled kunai laced with explosive tags. Amid the chaos of the blast, the two closed in once more, resuming their taijutsu duel. Yet even after thirty seconds of continuous exchange, neither had managed to gain the upper hand.
With both having activated their Sharingan, their reflexes and perceptions were evenly matched. If either wanted to win, they'd need something more, genjutsu.
As if on cue, both cast Sharingan illusions at the same time.
In an instant, the world around them shifted, they were pulled into each other's illusionary realm, their wills clashing in a deadly battle of the mind. Genjutsu duels were as dangerous as physical combat, if not more so; to lose here meant not just fatigue, but a shattered psyche and the possibility of permanent entrapment.
From a distance, Shisui watched the clash in silence, showing no intention of interfering. In his eyes, the moment Itachi had chosen to raise a blade against him, their friendship had ended. Now, Itachi was nothing more than a familiar stranger.
If this fight could awaken Sasuke's Mangekyō Sharingan, then Uchiha's power would surpass that of the Hokage faction. That alone would be worth the cost.
Just then, the Hokage and others arrived beside Shisui, having sensed the disturbance.
Orochimaru glanced at the fight and said, "So they finally started. I wonder whether the Sasuke I nurtured is stronger, or Itachi?"
Without shifting his expression, Shisui replied, "That's not something I care to guess. Their feud has nothing to do with me. But if Itachi wins, I will personally kill him."
"…"
Jiraiya looked at Shisui with mild exasperation. Clearly, Shisui was saying Sasuke could lose, but Itachi must not win. From his perspective, it made sense. It was hard to forgive what Itachi had done.
The Second Hokage narrowed his eyes at Sasuke. "Shisui, that boy Sasuke is on the verge of awakening his Mangekyō. Are you really letting them fight just for that?"
Shisui offered no denial and replied, "Second-sama really does see through everything. But whether Sasuke can awaken it or not still depends on his own strength. What, are you against Konoha gaining another combat asset right before the war breaks out?"
The Second Hokage gave a cold snort.
"I doubt it's just about the Mangekyō. Once the two siblings' eyes are combined, the Eternal Mangekyō is born. That's how Madara Uchiha achieved it, and you're walking in his footsteps."
Shisui paused, then chuckled. "Still hiding nothing from you, I see. So, will you stop it from happening? If you do, we're no longer allies."
"Hmph," the Second Hokage scoffed. "If this were the past, I'd give my life to prevent the birth of a new Mangekyō. But now that I'm already dead, I've lost all interest in you Uchihas. As long as you don't become Madara's pawns and don't harm Konoha, I'll look the other way."
Meanwhile, Orochimaru's eyes gleamed at the mention of "Eternal."
"Eternal Mangekyō... I'd love to study that."
Compared to the tense dialogue between the Second Hokage, Shisui, and Orochimaru, the conversation among the Fourth Hokage, Jiraiya, and Naruto was much warmer.
Both the Fourth and Jiraiya remembered Itachi from his childhood. Even before entering the academy, Itachi had shown prodigious talent. He mastered the Fireball Technique at just four years old.
Back then, before the Nine-Tails Night, the Fourth had already taken note of this Uchiha genius. He had hoped that, once grown, Itachi could be cultivated as a core leader in Konoha, helping to integrate the Uchiha into the village naturally.
Naruto, on the other hand, was simply worried about Sasuke.
Sensing their chakra levels, he knew Sasuke's was still inferior to Itachi's, and in the shinobi world, chakra often meant power. Sasuke winning this battle was close to impossible.
While everyone speculated, the genjutsu duel came to a close.
Both brothers staggered back, panting, eyes locked with grim determination. Itachi was the first to speak, a mocking tone in his voice, "Sasuke, you've improved over the years. Your taijutsu and genjutsu are almost on par with mine. But the Sharingan isn't about taijutsu or genjutsu. What matters is how far you can evolve it. Even if your eyes have reached the three-tomoe stage, they're still worthless before the Mangekyō."
"I won't use my ocular powers right away. I want you to feel the gap between us, slowly."
Before he even finished, Itachi unleashed a barrage of fire-style jutsu. With one-handed seals, he cast Phoenix Fire and Great Fireball in rapid succession.
Though not the highest-ranked techniques, their sheer power and intensity were lethal. The firestorms blocked Sasuke's vision and escape routes. If the flames merged, he'd be consumed instantly.
At that critical moment, Sasuke formed hand seals and growled, "Fire Style: Great Dragon Fire Song!"
Instantly, a colossal dragon of flame roared into the sky, not toward Itachi, but the clouds above.
The searing heat disrupted the sky, stirring layers of clouds into rolling thunderheads. The air crackled. Lightning dragons twisted and howled within.
Less than a second later, the storm unleashed its fury.
A lightning bolt in the shape of a Kirin plummeted toward Itachi at a speed too fast to track with the naked eye.
This was Sasuke's ultimate lightning technique: Lightning Style: Kirin!
The bolt struck Itachi dead-on, charring his body black and filling the air with the stench of burnt flesh. But Itachi didn't fall. Instead, he activated Susanoo. Crimson chakra coalesced into a massive warrior, enshrouding Itachi. Though it was only a half-body Susanoo, it was enhanced with two sacred treasures and still terrifying in might.
Facing Susanoo, Sasuke dared not underestimate him.
He activated his Heaven's Curse Seal and entered Ryūchi Cave's Sage Mode. Though imperfect and prone to losing control, it granted immense power.
With Sage Mode, Sasuke finally stood a chance against Susanoo.
After Sasuke and Itachi Uchiha's battle reached its climax, the Second Hokage widened his eyes and said to Shisui and Orochimaru, "So it's not just Kabuto Yakushi, even Sasuke has learned Sage Mode. No wonder you are brave enough to let a three-tomoe Sharingan brat fight against a Mangekyō Sharingan user. So you knew Sasuke had Sage Mode. If he manages to obtain the Eternal Mangekyō, his power might even approach Madara Uchiha's."
Shisui and Orochimaru exchanged a glance and said, "To stand a chance against Byakuya and Madara Uchiha, we have to prepare multiple countermeasures. Those two are genuine monsters, after all."
After a pause, the two looked toward the long-silent First Hokage and asked, "First Hokage-sama, do you think Sage Mode combined with Mangekyō Sharingan could defeat Madara Uchiha?"
"Me?"
The First Hokage looked momentarily dazed, then spread his hands and replied, "I don't know. Ever since I was brought back with Edo Tensei, I've been thinking about what I would say when I meet Madara again. But after so long, I'm not even sure if I can beat him anymore.
As for the fight between Sasuke and Itachi Uchiha, my opinion is that they should just shake hands and make peace. There's nothing that can't be resolved through a good talk. Surely killing your own family can't be the solution."
The First Hokage's words left Shisui, the Second Hokage, and the others speechless.
If Hashirama hadn't possessed overwhelming power, this level of naïveté would have gotten him killed countless times. But it was precisely his unmatched strength that allowed him to hold onto that innocence.
With absolute power, the First Hokage could afford to live by his own ideals.
Seeing Sasuke's body covered in curse marks and a pair of wings spread behind his back, Naruto exclaimed in shock, "When did Sasuke learn Sage Mode? Did he learn it together with Big Brother Kabuto?"
The Fourth Hokage and Jiraiya were also surprised, shocked at Sasuke's apparent Sage Mode.
From their experience, they couldn't see that Sasuke's Sage Mode was incomplete, but their own Sage Modes weren't perfect either.
For a ninja, even partial mastery of Sage Mode was already exceptional.
Hearing Naruto's comment, Yakushi Kabuto shook his head, "Sasuke hasn't mastered Sage Mode. That's the power of the Curse Mark. It's the ultimate goal of Orochimaru-sama's experiment. He wanted to allow ordinary ninjas to harness natural energy."
"To let ordinary ninjas harness natural energy…"
At that, not just the Fourth and Jiraiya, even the Third Hokage was visibly shaken.
He had never imagined that his former student, Orochimaru, harbored such ambition. And at that moment, he also felt a pang of regret, regret for not correcting Orochimaru sooner.
If Orochimaru had stayed on the right path and developed a complete Curse Mark technique, the strength of Konohagakure might have reached a new peak. They might no longer be threatened by Kumogakure or Iwagakure.
Noticing the Third Hokage's gaze, Orochimaru turned to look at him. His eyes were filled with cold indifference, and a mocking smile tugged at his lips. He respected the Third Hokage as a teacher, but that didn't mean he could tolerate Konoha's rigid rules. A teacher like Hiruzen, who always adhered to the rules, would stifle any burgeoning creativity before it had the opportunity to flourish.
After a long, drawn-out battle, Sasuke and Itachi Uchiha were both on the brink of collapse due to chakra exhaustion.
Sasuke could no longer maintain his Curse Mark state, and even Itachi was unable to keep up Susano'o.
Still, neither stopped fighting.
They returned to the most primal form of combat, each gripping a kunai and slashing at one another, leaving gashes on each other's bodies.
With the sound of steel slicing through flesh, Sasuke landed a new cut on Itachi.
Then he pushed Itachi to the ground and pressed his kunai to Itachi's neck, speaking coldly, "Itachi, tell me now, who's stronger, you or me?"
"Weren't you after my eyes? Come and take them if you have the guts!"
Unexpectedly, Itachi Uchiha laughed and looked up at Sasuke, "Sasuke, you've done well. Even without unlocking the Mangekyō Sharingan, you've already reached the level where you can defeat me. That makes me very happy… because it means you're finally strong enough to protect yourself. After I die, go ahead and transplant my eyes. Then you'll have a pair of Mangekyō eyes, and you can serve the village with a clean conscience, bringing glory to the Uchiha clan."
"What's that supposed to mean? Are you asking me to spare you?"
Sasuke glared at him, eyes full of suspicion. "Or are you trying to provoke me, then strike while I'm distracted and steal my eyes?"
Itachi shook his head, mocking himself, "Sasuke, I never wanted to kill you, nor did I ever want your eyes. My goal has always been to make you stronger. Back when Shisui used genjutsu to control Danzō, I could've admitted my mistake and returned to the clan. But I refused. First, because my return would've tipped the village into the clan's hands. Second, because I wanted you to become truly powerful.
If you had always lived under the protection of our parents, Shisui, and me, you would've never surpassed jōnin level. You might not even have awakened the three-tomoe Sharingan, you would've lived your life in mediocrity."
Itachi paused for a moment before smiling, "But by defecting, I made sure Shisui wouldn't dare move against the village. And you… you could live driven by hatred toward me, using it to keep getting stronger, until the day you awakened the Mangekyō. Judging from your current strength, I'd say my plan was a success. It's just a pity you haven't awakened the Mangekyō yet. That's the one thing that disappoints me… Maybe I wasn't cruel enough. That's my failure as your brother… I'm sorry."
Itachi's words completely shattered Sasuke's self-control.
A surge of negative chakra burst forth like a tidal wave, flooding into his eyes.
In the blink of an eye, they transformed into the Mangekyō Sharingan.
Seeing those eyes, nearly identical to his own, Itachi's lips curled into a faint smile, "You finally awakened it. I lied about everything I said just now… my foolish little brother."
Suddenly, Itachi thrust both hands forward, reaching for Sasuke's eyes.
But Sasuke had noticed something was wrong.
He pressed the kunai at Itachi's neck down harder, just as he was about to end it…
A short blade blocked his kunai.
The person who stepped in was none other than Uchiha Shisui, who had been silently watching the whole time.