Chapter 99: The Multi-Core Brain
After Kabuto returned to the Konoha orphanage with Nonō, Nan's true body awoke as well.
Once again, he marveled at the strange sensation of moving two bodies at once. Kabuto's existence felt like having a permanent Shadow Clone—but unlike ordinary clones, this one was far more refined.
A regular Shadow Clone did not share thoughts with its creator. Only when the jutsu was dispelled and the chakra returned would the clone's experiences flow back to the original.
Nan and Kabuto, however, constantly exchanged chakra, keeping their minds perfectly synchronized in real time.
It resembled the bond between Nan and his Phantom Body, though the latter was different: the Phantom Body had only the faintest trace of awareness, barely enough to follow simple orders. It lacked initiative and higher thought.
Kabuto's transformed body, on the other hand, could think independently and act freely, while still being one with Nan's will. This, Nan realized, was what a true clone should be.
Several days had passed since he gained this "double," and Nan was gradually adjusting to the sensation of operating two brains at once. Then, a bold thought struck him—if both minds were linked, could one brain directly control the other body?
To test the theory, Nan had set up an experiment.
The night before, as his real body drifted to sleep, he summoned a Phantom Body to keep watch. He had already discovered that his conscious mind could slip into the subconscious of the body that was asleep. But he had never tried to control it.
This time, with Kabuto's mind awake, he attempted to direct his true body.
Concentrating, Nan imagined controlling himself the same way he guided a Phantom Body. To his delight, his sleeping form slowly sat upright, then flexed its fingers.
The sensations fed back to Kabuto's brain were no different from his own. Both minds were identical—two processors running the same will. And it worked. He could truly control another body.
The realization thrilled him.
Ordinary humans, if compared to machines, were like single-core processors. A person could only focus on one task at a time. Those who seemed capable of multitasking were merely shifting their attention rapidly back and forth.
But Nan, with two fully functional brains, could dedicate one entirely to each body. He could perform two different actions at once, true multitasking—his mind had gone from single-core to dual-core.
His thoughts drifted back to Kakashi's explanation of why Minato never completed the Rasengan with nature transformation. The Rasengan's shape alone demanded total focus; there was no room to simultaneously control elemental change.
Humans could not look left and right at the same time. That was why Naruto had relied on Shadow Clones to juggle both. Only later, with the Nine-Tails' highly responsive chakra, could he wield the Wind Release: Rasenshuriken alone.
Nan, however, no longer needed such tricks. With his dual-core mind, he could theoretically form the Rasengan while simultaneously applying nature transformation—without help.
The applications didn't stop there.
He remembered Naruto and Sasuke's joint technique: Scorch Release: Halo Hurricane Jet-Black Arrow Style Zero.
The move had long puzzled him. By all logic, kekkei genkai required a unique bloodline limit. Two shinobi combining jutsu shouldn't have been able to create an entirely new chakra nature. Even the Third Hokage, with multiple Shadow Clones and mastery of all five elements, had only achieved combination jutsu, not new elements.
Nan now suspected that bloodline users were simply exceptionally attuned to blending chakra natures. Their physiology allowed them to perfectly align two different properties.
Naruto and Sasuke, however, had a special advantage. The Nine-Tails could finely tune its chakra's qualities when lending it to Naruto, while Sasuke's Mangekyō ability to manipulate flames (Amaterasu) gave him extraordinary precision. Together, they could sense each other's chakra in fine detail and adjust instantly—creating a new property on the spot.
For Nan, this was a revelation. His dual-core consciousness meant he could control two chakra natures simultaneously with perfect internal coordination. He lacked the shortcuts Naruto and Sasuke had, but with practice, he was confident he could discover the key to merging natures himself.
The moment the thought crossed his mind, Nan couldn't resist. As soon as he woke, he eagerly began testing it out.
Could he truly wield two chakra natures simultaneously?
His strongest affinities were Fire Release and Lightning Release, so it was only natural to start there.
Focusing his chakra into both hands, Nan split his concentration—one mind to the left, the other to the right. He envisioned flames roaring in his left palm, and lightning crackling in his right.
The result came instantly.
The soft blue chakra in his hands suddenly shifted: on the left, it blazed into searing fire; on the right, arcs of electricity coiled and snapped in the air.
It worked. He had confirmed it—he could manifest two elemental natures at once. And, surprisingly, it wasn't any harder than performing a single transformation.
But Nan did not rush to attempt a fusion.
Creating a new kekkei genkai was no trivial matter. Rushing headlong into it would be reckless.
Besides, Fire and Lightning—he had never once seen them combined in his past life's anime, manga, or novels. He had no idea what their union might produce. Testing it inside his home was asking for disaster. One wrong move, and he could burn or blast his own house apart.
Meanwhile, through Kabuto's body, he could faintly taste the simple breakfast Nonō had prepared. That only reminded Nan that, while their minds were linked, their stomachs were not.
The clone might be full, but the real body was still hungry.
Sighing, Nan glanced around his dusty kitchen. He had been away too long; there wasn't a scrap of food left. He would have to head out and buy something to eat.
He had just slipped on his clothes and reached for the door when—
Ding-dong.
The bell rang again.
Nan paused, frowning. Very few people even knew where he lived. Beyond a handful of Uchiha clan members, only Kakashi, Guy, and perhaps one or two others might drop by.
But who would come calling at this early hour, right as people were sitting down to breakfast?
Nan's eyes narrowed, curiosity piqued.