The sun began to set behind the trees as Itachi, panting, let go of the mini Rasengan he was still trying to hold in his palm. The sphere dissolved in a whirlwind of wind and silence. His legs were trembling. His chakra had been completely exhausted.
He collapsed onto the damp grass and took a deep breath, feeling how his body was empty, drained. "Does it consume too much… or am I just too weak?" he wondered quietly.
It was the first time he had pushed himself to that extreme. The Rasengan, though powerful, seemed to demand an ocean of chakra that he didn't yet possess. Perhaps it was a matter of practice. Perhaps it was a matter of efficiency.
But what truly bothered him wasn't the exhaustion, but what had happened before: he had used a genjutsu on himself, and it had altered reality. The brain in this world wasn't like the one in his previous life. Here, thoughts had the ability to reconfigure chakra flows and make them tangible.
Itachi lay back and began to organize his hypotheses: In the other world, the brain only processed information and generated internal illusions, imaginations with no physical impact. In this world, the brain, connected to chakra, could alter perception and, if the illusion was strong enough, also affect reality. The self-genjutsu he applied didn't just deceive him; it activated his brain as if it were a catalyst, forcing his body to execute what had previously seemed impossible.
"If I can achieve that with a Rasengan… what else could I force my mind to do?" he thought, feeling a spark of excitement despite his fatigue.
Itachi formulated a risky idea: what if he could train his brain like a muscle, using chakra to stimulate different areas? He might be able to: Accelerate his thoughts, as if they were thousands in parallel. See problems from multiple angles, alternating between cold logic and spontaneous creativity. Use his brain as a supercomputer, capable of instantaneous calculations and connections impossible for a normal mind.
It was only a theory, but now he had a clear path: to learn how to directly link chakra and his brain.
The wind blew through the branches, and the three-year-old closed his eyes, exhausted but satisfied. He had discovered something no one else seemed to see: the brain was a fertile ground for chakra, and a power even more dangerous than any physical jutsu was hidden there.
He smiled, almost amused. "I don't need more strength yet… I need more control," he murmured.
Exhaustion overcame him. As he fell asleep, the theory throbbed in his head like a secret of the universe waiting to be unearthed.
When he opened his eyes again, it was a new day, and Itachi decided not to train. The chakra exhaustion still weighed on his body, and his mind needed rest. He walked through the corridors of the house, stopping at every detail he had never appreciated before: the scent of freshly polished wood, the scrolls with the Uchiha fan hanging on the walls, the sound of his mother in the kitchen, the distant murmur of the neighbors.
He walked through the streets of the district. Young ninjas were training in the yards, elders chatted in the shops, and children ran with toy kunai. It was a lively village, proud of its heritage. But in Itachi's mind, everything was tinged with a dark color: "All of this… is going to disappear."
He clearly remembered what he knew from his previous life: the Uchiha clan massacre. The blood, the silence, the end of a thousand-year-old story. Although he wasn't the exact link to that destiny, there was still Danzō, the man in the shadows who would never stop seeing the Uchiha as a threat.
And beyond Danzō, the most chaotic event was still pending: the Kyūbi's attack. The power of the Nine-Tailed Fox that would devastate the village, and the beginning of the end for so many.
Itachi clenched his fists. For the first time, he clearly felt he was walking on a historical minefield, where every decision could or could not alter the inevitable.
That afternoon, the calm of the district was interrupted by an Anbu looking for Fugaku. The expression on his father's face said it all: an urgent, dangerous mission.
"The situation in Kusagakure is getting worse," Fugaku explained briefly before leaving. "The Rock has intensified its movements. The Third Tsuchikage wants to break our defensive line and cut off the supply to the Leaf."
Itachi listened carefully, trying to piece together what he remembered from the anime with what he was living firsthand. He knew they were in the Third Great Ninja War, but now the distance between history and reality was blurring.
The Iwagakure ninjas had the advantage of the terrain: they could slide underground to attack by surprise or escape an ambush. To counter them, Konoha was deploying many sensory ninjas, who had to detect hidden chakra signatures. It was a constant game of chess, where every mistake cost lives.
"It's not just training I need," Itachi reflected as he watched his father prepare. "I need to understand how this world works in times of war."
Fugaku, before leaving, leaned towards him. "Take care of your mother. And observe, Itachi. The clan is measured not just by its power, but by how it faces storms."
The boy nodded in silence.
That night, as he went to bed, Itachi reviewed the memories of his past life and mixed them with what he saw now. The Rasengan had shown him that the mind could force the impossible. The Sharingan had been awakened by a strong emotion, not by cold training. He now understood that chakra and the brain could intertwine to expand human capabilities.
But all of that paled in the face of the magnitude of the events to come: an ongoing war, invisible enemies underground, and a future where the entire clan could disappear.
Itachi squeezed his eyes shut. "If I'm going to change something… I need more than power. I need to understand the very essence of this world."
Silence enveloped him, and although he tried to sleep, his mind remained active, weaving theories, plans, and questions. The Uchiha boy was no longer just training to be strong; he was training to face destiny itself.
After a full day of rest and reflection, Itachi returned to training. He knew that if he wanted to progress, he couldn't limit himself to chakra control and illusion. He needed something more: structure, precision, technical knowledge.
The first thing that came to his mind was seals. Fūinjutsu was an ancient, complex art, capable of sealing weapons, spirits, and even legendary beasts. An art that could give him not only power but also control.
The problem was obvious: "I'm three years old… no one will take me seriously."
And besides, his parents were strict about his safety. Outside the Uchiha district, his movements were restricted. He couldn't just go and find a master from the Uzumaki clan or an expert ninja from the village.