Scorpion had already finalized the theory behind the Rebirth Core, but he had never put it into practice. The method of its creation bore similarities to the Chakra Core found in human puppets.
Both required isolating the region in a ninja's body with the highest chakra density while still alive. This tissue had to be carefully preserved using intricate methods before it could be refined through sealing techniques. The end product was a core capable of wielding the chakra and ninjutsu the individual had mastered in life, preserving their combat ability to the greatest extent.
The more completely one preserved this chakra-rich tissue, the closer the puppet's strength would mirror its former human state. However, such tissue lost its vitality in the process, which meant that puppets could not generate chakra on their own. Instead, a puppeteer had to supply chakra to the puppet through threads, rendering it a lifeless shell, albeit a powerful one.
The Rebirth Core, however, went a step further. It preserved not only the tissue but also its activity. By infusing it with specialized chemical solutions in regular intervals, the core could simulate the regenerative capability of living flesh. It would continuously produce chakra, just like a living person. That innovation was what earned it the name: "Rebirth Core."
The final and most delicate phase involved a forbidden Sunagakure sealing technique that allowed for the transference of consciousness. Only once this was performed would the Rebirth Core be complete—a vessel for chakra, spirit, and the self. From there, it could control a puppet body as a living mind inside an artificial shell.
When Akira first examined the design for the Rebirth Core from the fragments of Scorpion's mind, his initial reaction was disbelief—followed by dismay. The procedure was radical, extreme, and grotesque in its sacrifice.
To extract the high-density chakra tissue from one's own body would require severing a core piece of oneself. While not instantly fatal, it would inflict damage so devastating that even survival would seem like a punishment. One would lose massive chakra capacity, perhaps permanently cripple their body, and worse—the final step required abandoning the body altogether, discarding one's humanity to live on as an artificial construct.
To Akira, such a path was madness.
He had studied physics, chemistry, biology—he understood better than most how unfathomably intricate and powerful the natural human body was. To throw that away for the illusion of immortality was not a tribute to art, as Scorpion believed, but a betrayal of the highest art nature had ever crafted.
But just as he prepared to dismiss the Rebirth Core as a vain pursuit of a deranged genius, a new thought surfaced.
The clone he had stationed in the Forest of Death—a tree clone, rich with chakra but limited in use—suddenly came to mind. Its purpose had been observation and backup, yet it possessed one trait critical to the Rebirth Core: stored chakra.
"Wait... What the Rebirth Core needs isn't the flesh itself, but the chakra infused within it."
If chakra was the true ingredient, perhaps the medium didn't need to be human flesh. What if he extracted a portion of the tree clone—sufficiently saturated with chakra—and used that in the Rebirth Core procedure? As long as the activity of the tissue could be preserved, and the chakra continually cycled...
"Then, by keeping the core tethered to the clone's network, I could skip the consciousness transference step entirely. The connection would already be there."
Akira froze.
This idea... It was feasible. Theoretically sound. Revolutionary. His mind buzzed with calculations, possibilities, and configurations. What had seemed a useless relic of Scorpion's deranged ambition now shimmered with new potential.
Elsewhere, the Anbu who had witnessed the aftermath of Akira's battle with Scorpion arrived at the Hokage Tower, kneeling before the Third Hokage.
"Reporting in, Lord Third. We've discovered signs of a fierce battle in the forest north of the village.
Based on the remnants and tactical marks, we suspect one party was a puppeteer from Sunagakure. The other's identity remains unknown."
The Third Hokage's expression darkened as he listened. War with Sunagakure had ended. They were mere steps from signing a formal alliance. So what did it mean for a Sunagakure ninja to be fighting near Konoha now?
Was it a breach of the truce? An attempt to provoke war? Or something else entirely?
"This is not something to take lightly," Hiruzen muttered. "I'll see it for myself. Lead the way."
When they arrived, the scene stunned him.
Flattened trees, deep gouges in the earth, poisoned weaponry scattered about, and the wreckage of scorched puppets. It looked less like a skirmish and more like a battle between titans.
Captain Akagi, already investigating on-site, approached the Hokage.
"Akagi, what have you found?"
"Lord Third, we can confirm only two individuals engaged in combat. However, a third individual was present briefly but did not interfere."
"Blood traces indicate only one was injured. The other seems completely unscathed. There are no corpses, so we can't determine if the injured party escaped or was taken."
"The attackers were thorough. Most traces were carefully covered. However, from a few overlooked footprints, we believe at least one of them came from Konoha."
"The other two left no discernible trail."
Hiruzen stroked his beard, thoughtful. Scorpion's puppet parts were unmistakable. But the destruction?
"Have you identified the ninjutsu used by the other party?"
Akagi hesitated. "Unfortunately, no, Lord Third. There are few clues, but we did discover something strange—gigantic footprints.
They resemble skeletal structures of some massive creature. Possibly a summoning beast, though we couldn't identify it."
Hiruzen's eyes widened.
"Footprints like bones? Take me to them. Now."
They walked to a clearing where deep footprints lined the battlefield. Next to them, a spiral pit marked the ground—the remnants of a powerful defensive jutsu. But it was the prints that caught Hiruzen's breath.
He had seen them before. On the battlefield in the Land of Wind. He knew their shape by heart.
"These... These are from Susanoo. I'd stake my life on it."
There was only one person in recent memory who had summoned Susanoo outside the Uchiha clan—Uchiha Kawa. Or rather, Akira.
The Third Hokage's mind raced. Why was Akira here? Why clash with a Sunagakure ninja again? And who was the third spectator?
Questions. So many questions. Yet the answers were elusive.
He turned to Akagi.
"Sunagakure's delegation arrives soon. Perhaps they can shed light on why their puppeteer was here. We must tread carefully. One wrong step, and we'll plunge back into war."
The wind whispered through the trees, carrying with it the scent of scorched wood and blood. And far away, Akira sat in silence, a thousand plans forming in his mind as he stared at a new blueprint—his version of the Rebirth Core.
This was no longer just Scorpion's dream.
It was his evolution.