Chapter Text
The moment the smoke cleared; sorrow took over his mind. Kirin, his greatest invention, untainted by Kakashi or by Orochimaru, unrelated to the memories of this man, or to Naruto. It had been his greatest success in his illicit training trip.
Because even with the Uchiha compound turned to nothing but ash and rubble, even with the Amaterasu’s flames being extinguished as their targets were flattened either by the shockwave or the initial explosion. Itachi was alive, relatively unharmed even.
The blood tracks under his eyes were still there, and so were the scrapes and burns they’d both accumulated over their fight. But Itachi’s body didn’t have the telltale lightning scars, his hair wasn’t spiked from the current, and he certainly wasn’t dead.
Itachi’d been right earlier, when he’d claimed that Sasuke was out of chakra, though they had both known that Itachi’s reserves weren’t faring much better. The Dragon Flame Jutsu was far superior in heat and force output then the generic Fireball Jutsu, but the chakra drain was equally as immense as the technique was powerful.
He’d thought he’d needed a Kirin that powerful. One that would bypass any of Itachi’s arsenal from his never-ending bag of tricks. But he was wrong. And as he saw Itachi stumble to his feet, he knew he needed something new.
So, he remembered.
The Sharingan was famous for its ability to copy techniques, that ability was always the one noted first in the Bingo Book pages of Sharingan users, even back when there’d been over 40 Uchiha in the International Bingo Book (he’d know, he had over a dozen copies at the compound).
The real truth to this ability was that the Sharingan made it impossible to forget. Memories were held in the chakra streams of the Sharingan’s eyes for as long as they worked. Sasuke’s were no different. It was those memories he sifted through to find his next weapon.
With 3 years of heavy usage on his Sharingan, Sasuke had plenty of things he could visit. But today he visited a catalogue in his mind that he just called ‘Jutsu’. There were many useless articles there, a dozen memories of Naruto preforming the Shadow Clone jutsu, half that from his first viewings of the Chidori, as well as nearly a hundred memories of his own attempts to modify the jutsu into his own uses.
It was when his search narrowed down to Orochimaru when he slowed the pace slightly. The man had been a genius, he’d claimed to have known nearly 4,000 jutsu once. He’d shown maybe 300 to Sasuke in their trainings together. and after awhile he came to 2 memories that stood out to him.
The first was as usual for the first year, Orochimaru had him come into the training room so Sasuke could be shown a technique that was beneficial to “enhancing his body” whether that was a subset of medical jutsu that could only be applied to oneself to accelerate muscle growth or a technique to self-train using genjutsu of your greatest opponents.
It wasn’t the actual technique that interested him here. It was the part where Kabuto appeared, proclaiming that he had a report for his master. 13-year-old Sasuke had taken the interruption as a chance to take a breather. But then he’d watched as Orochimaru had touched Kabuto’s shoulder, the chakra flow had taken an immediate turn in the direction of the snake’s hand.
After a moment, he’d let go, and Kabuto had slumped slightly, before walking out. When Sasuke asked what Orochimaru had done to him, he’d said:
“I absorbed some of my chakra from Kabuto’s own curse mark.”
“Why? he was supposed to be reporting information wasn’t he?” Sasuke had questioned.
“So naïve, little Uchiha,” he’d smiled widely here, “Do you think speaking is the only way to share knowledge?”
It had been obvious then what he’d done. The jutsu had allowed Orochimaru to take Kabuto’s chakra and his knowledge, likely straight off the information transmitted throughout his chakra pathways. It was this memory, along with the sickening memories of being handled by massive tongue-like tentacles in that ethereal realm inside of souls that spurred him onto what he did next.
One moment, Sasuke’s eyes saw Itachi, still on his hands and knees even throughout the whole inner searching he’d done. The next moment he was in a realm of tentacles and death. The inner world of the Cursed Mark on his neck.
Orochimaru was there, face utterly neutral due to the immediate genjutsu he’d placed on him when the man’s eye had snapped onto him in reflex. He walked forward through the writhing flesh. It only took him 6 steps before he was in front of Orochimaru. He held out his palms thinking.
He wasn’t proficient enough in this technique to even try to use it with no seals like Orochimaru had been. But he didn’t need to be. Hand Seals were just ways of influencing the chakra in your body into a certain flow. He knew the flow and he knew the signs that would achieve that flow. He started weaving slowly: Rat…Ox…Bird…Ram…Boar…Hare…
He held his chakra for a moment before he shot his hands forward to grasp Orochimaru’s jaw. For a second there was nothing.
And then there was pain.
He screamed, maybe just in this world or maybe in the real one too. Energy so immense he could barely comprehend it flowed into his body. Knowledge and memories so intense and so plentiful it immediately caused his facial extremities to start dripping blood. But still he held on, because Sasuke was no stranger to pain and painful memories. And Itachi was dying today. No matter how much pain he needed to take.
It could’ve been a second or it could have been a millennia, but the pain began to fade. The immense Chakra settled into his pathways and the memories tucked into the part of his brain where all his trauma was waiting. And when he opened his eyes, it was to Itachi staring at him with shock, so very clear on that perpetually blank face.
He almost wanted to see the snarl on his own face after that. He welcomed the bloodlust. Because he had the overwhelming advantage now. He felt practically fresh as new while Itachi was about as strong as a tumbleweed.
His hands blurred into hand seals, so fast he couldn’t see them himself. In half-a-second he ran through the 37 seals for this Jutsu, and once the chakra flow was perfect, he slammed his hands to his chest.
He was sure his voice reached the heavens when he yelled out “Eight-Headed Hydra Jutsu!”
There was a massive poof of smoke, and a gross squelching of flesh as the snake grew. Sasuke’s perception octupled. His range of vision rose high above the trees around them, his new, massive nostrils breathed in smoke filled air, but didn’t cough. After a moment to gather himself, Sasuke peered down at the tiny form that was his clan’s murderer. Sasuke’s snake-head grin must’ve looked terrifying to his prey. He hoped it was.
With a sharp *crack* the air was pierced by 8 building sized snake snouts shooting towards the ground. But suddenly, before Sasuke could flatten Itachi into the rubble, his massive heads suddenly were slammed against an equally massive, and far greater defensive force. Because right in front of him was a massive ethereal red-orange demon. It lacked any sort of bottom half, but the armory it carried up top showed that it wasn’t lacking in ability.
He snarled again and controlled two of his heads to attack the right side and sent 3 to the left. While he would attack up top, hopefully avoiding the demon’s shield. The clashes caused massive clanging noises to sound out, and great shockwaves of debris were blown about at every clash of snakehead and shield.
Even with his lack of progress he continued firing forward with his heads. Avoiding the sword swings as well as he could with his lack of experience with this body. Quickly though, the chinks in Itachi’s armor began to show. Not the demon’s armor, mind you, but his swings began slowing down and his demon was being pushed back further by each physical clash.
Then Sasuke made a mistake.
He’d gotten overconfident, charging in with a greater resolve than before, uncaring if he got hit by the blade he hadn’t viewed as anything special. But then Itachi cut off one of his heads. For a moment Sasuke was frozen as he watched the veritable sea of blood spurt off the equivalent of one of his arms or legs.
And in that moment of freezing, Itachi struck. The demon’s great blade came suddenly towards his main head. It was a stab this time, not a slash. And then Sasuke was in a sea of pitch black. The only thing he could hear was the sickening roars of his former heads. Before a ray of light speared into the abyss and he saw what was happening.
The snake body was being sucked into the sword. Sasuke panicked, a Chidori was charged up with none of the seals he needed to keep from harming himself. He used that panic Chidori to slice off his connection with the great snake.
He was dropped to his knees after that, breaths heaving and eyes blurry. The Eight-Headed Hydra was far more chakra consuming than he’d expected. Though perhaps it was only because of the length of time he was using the form. But he was fine, after a moment of recovery he stood up, and met Itachi’s eyes over the heaps of flesh being absorbed into the demon’s sword.
And then it flickered out. Itachi’s demon shield first lost its armor, then its muscles and then its skeleton seemed to simply shatter above his head. The murderer of his parents fell to his knees and once again coughed a sizable pool of blood.
Itachi was done.
Sasuke practically waddled over to him, gait slow both from pain and the realization that his lifegoal was seconds from fulfillment. He stopped some 3 meters from the corpse to be.
His voice was immensely smug as he said: “I told you Itachi, my hatred has brought your death into reality.” As he looked at the pathetic form on the ground, Sasuke decided he would be better. He’d let this unrepentant murderer have his final words.
“Any last regards? A prayer to some deity? A curse to your partner? Forgiveness maybe?”
Itachi looked up at him, dared to smile, and said: “Just remember Sasuke, I will always love you…I’m sorry for everything I’ve done. Try to see the good in the world with my eyes, won’t you, little brother?”
In a second, Sasuke blinked, and the next Itachi’s throat was slit. The Kusanagi hovering in the air through telekinetic control. ‘Just like Orochimaru’ he thought.
He stared blankly at Itachi’s corpse. His face was peaceful in death, unlike any of his victims…strangely Sasuke wasn’t angry at that thought anymore. He’d avenged his clan.
He felt…peaceful.