Sasuke vs Itachi

"Finally found you, Itachi," Sasuke's annoyance grew as he saw how casually Itachi sat on a chair, seemingly unconcerned about his presence and looking down at him from a higher position.

"Didn't I say, don't come looking for me until you have the same eyes as me? Or do you think you've gained the power to kill me? Indeed, you're still so arrogant."

Though he said this, in reality, Itachi had secretly guided Sasuke to him using his crows. Otherwise, given Sasuke's current strength, it would have taken him quite a while to find Itachi, assuming he could even find him. His body was near its limit, sustained primarily by medication. Even if Sasuke didn't come, Itachi would have eventually gone after Sasuke, since the medication was running out. 

"Hmph, my eyes are no longer what they used to be. I can see through your genjutsu now," Sasuke spoke, but the truth was, he had never seen through any of Itachi's genjutsu. Comparatively, his skill in genjutsu was like a small snake compared to a giant dragon. Along with the gap between their Sharingan stages, Sasuke seeing through it would have been odd; everything was under Itachi's guidance and control.

"Is that so?" Itachi kept his 3-Tomoe Sharingan active the entire time. The two of them stood still, while Black and White Zetsu on the side were rather speechless. Fights involving genjutsu were among the most uninteresting, at least for observers, as they seemed to be standing in one place.

Of course, this was only for observers. For Sasuke, being trapped in a genjutsu was nearly as real as the physical world. Itachi's genjutsu showed him the origins of the Uchiha clan, the growth of Madara and Izuna Uchiha, including the Mangekyo Sharingan, and even the entirety of the Eternal Mangekyo Sharingan.

Itachi used this approach to prove that he aimed to take Sasuke's eyes, intending to trigger Sasuke's deepest hatred for him. Then he would kill Sasuke, using the power of his Mangekyo as guidance, ensuring Sasuke could unlock the Mangekyo himself.

"Even though Madara activated the Eternal Mangekyo, he has been a failure throughout history. From being defeated by Hashirama in the past to being defeated by the Fourth Hokage in the present. Only I can surpass Madara and become the closest thing to the pinnacle of existence," Itachi grinned demonically.

And Sasuke fell right into his trap. After witnessing Itachi's genjutsu, Sasuke naively believed that Itachi truly intended to take his eyes. Fueled by anger, he finally attacked. Simultaneously, Itachi dispelled the genjutsu, and the two engaged in a clash of shuriken.

"Shurikenjutsu." Using the insight of his Sharingan, both of them continuously hurled waves of shuriken at each other. However, each shuriken clashed with its counterpart, creating a spectacle of clashing metal echoing in the air.

"Clang! Clang!"

Countless shadows darted back and forth, the sound of shuriken colliding resounded. After a prolonged exchange of shuriken and occasional kunai, both felt they had exhausted the shuriken's utility. So, they transitioned to close combat. Sasuke, as the first to strike, employed his Chidori-powered lightning-charged feet, racing toward Itachi with utmost speed. He drew his Kusanagi Sword with his right hand while his left hand formed a fist aimed at Itachi's face.

However, from Itachi's perspective, all these movements appeared slow. While he knew his brother was easily fooled, Sasuke wasn't a complete idiot.

If he made his hold-back too obvious, Sasuke would have caught on, so Itachi had meticulously planned this battle. He needed to ensure that Sasuke learned to fully utilize his Sharingan during this fight, even mastering the Mangekyo Sharingan's techniques. Every step of the battle was a calculated move on his part.

Itachi extended both hands. He gripped Sasuke's wrist, preventing him from unsheathing the Kusanagi Sword, while his right hand caught Sasuke's left fist like an eagle's talon, immobilizing it.

"Shadow Clone Jutsu!" Just before these actions, Itachi had already formed the hand seals for the Shadow Clone Jutsu. A clone appeared behind Itachi and hurled three kunai at Sasuke.

"He can still form seals in an instant?" Sasuke was taken aback, but not overly concerned. A white barrier emerged where the cursed seal was, blocking the kunai and biting Itachi's hand. This forced Itachi to release his grip.

"Fuuma Shuriken!" As the white barrier disappeared, Itachi launched the Chidori-embedded Fuuma Shuriken. This not only cut through the kunai and Itachi's arm that he had blocked, but the severed Itachi also transformed into a crow. Simultaneously, Itachi reappeared right in front of Sasuke, moving faster than Sasuke's Chidori-powered lightning chakra-charged feet.

He landed a kick on Sasuke's abdomen, sending him flying and crashing into a wall, leaving a deep dent. Itachi swiftly closed the distance again, his foot landing on Sasuke's foot before another punch struck Sasuke's stomach. The blow caused a sharp pain in Sasuke's abdomen, and then Itachi reached for Sasuke's eye, gouging one of them out.

"Argh!" Sasuke's face turned pale, and he cried out in pain. Just then, the curse seal resonated with Orochimaru's chakra. It seemed Itachi had anticipated this, so he deliberately withdrew his dōjutsu, pretending that Orochimaru's intrusion disrupted the chakra within Sasuke, thus breaking the genjutsu.

In reality, if Itachi had intensified his dōjutsu, even if Orochimaru injected this amount of chakra, unless Orochimaru played his trump card, it would have been ineffective. After all, the combination of Itachi's genjutsu and Mangekyo was no laughing matter.

"I've said it before, even if you possess the Mangekyo Sharingan, I will use my hatred to turn illusions into reality," Sasuke conjured two more Fuuma Shuriken and hurled them at Itachi.

If Ryoha were present, he would have exclaimed, "Sasuke, you're quite the fool!" Even if Itachi's previous genjutsu had been disrupted and backfired, given Itachi's skill and the insight of the Mangekyo, he could easily evade. Was it really necessary to clumsily pass through the middle of the spinning shuriken like a circus trick, allowing the hidden shuriken to hit you?

Wasn't that just absurd? He could have evaded and retreated without directly exposing himself to such danger. Moreover, Itachi's genjutsu backlash was something he had deliberately allowed, a fact only Sasuke, with his arrogant mindset, would declare turning illusions into reality.