Itachi had spent weeks perfecting the flow of electrical chakra and magnetic fields. His experiments with superconductor threads and the small Gauss cannon had given him an idea: if he could manipulate metals with chakra, why not protect himself from attacks with them?
Sitting in the courtyard, he concentrated his energy and drew a series of seals in a circle around him. Guiding the chakra flow through them, he began to create a stable magnetic field, invisible but powerful.
"If this works," he whispered, "any metallic object that approaches will be repelled… or deflected."
Renji was by his side, with a stick in his hand and sand all around. "Itachi, do you want me to draw the seals too?" he asked, eager to help. "Yes," Itachi replied. "Draw the exact patterns I tell you. If they're precise, the flow will be stronger and more stable."
While Renji traced the seals following Itachi's instructions, he placed small shuriken and pieces of metal to test how they reacted to the magnetic field. With each adjustment, Itachi could feel how the energy flow was being directed correctly and how the metallic objects were being repelled or deflected.
"Try varying the angle of the shuriken," Itachi said. "Observe how the field affects them." Renji placed the projectiles in different positions and noticed something curious: some bounced farther away depending on the direction of the seals. "Look!" he said excitedly. "By changing the pattern's orientation, the shuriken goes somewhere else."
Itachi smiled. "Exactly. Your intuition for patterns is useful. Even if you don't feel the chakra, you can influence how it's channeled."
Soon, the shuriken began to fly across the courtyard, deflected and accelerated by the Gauss effect, as if they were launched again by the energy itself. The shield wasn't just defensive; it could redirect attacks toward specific points, transforming a simple experiment into a complete combat technique.
Renji, although he still didn't understand everything, was proud to participate. "I never thought drawing in the sand could do this," he said with a smile.
Itachi closed his eyes for a moment, concentrating. "This is barely the beginning. If we can control metals, electricity, and chakra flow like this… the possibilities are infinite."
That night, as the moon rose over the Uchiha clan, Itachi knew that teaching and experimenting alongside Renji not only accelerated his learning but also gave him new perspectives. His secret path toward understanding the ninja universe was advancing by leaps and bounds.
The shield was a success, but Itachi's mind was already at the next level. If magnetic fields could repel a shuriken, could they also accelerate a projectile to lethal speeds? He walked with Renji to a more isolated part of the courtyard, where a large, mossy rock lay.
"Renji, I need a new series of seals," he instructed, his voice low and serious. "Draw a long, straight line, like a barrel. Add containment and acceleration runes. And at the end, a discharge symbol."
Renji, sensing the magnitude of the new experiment, began to draw with a shaking hand. He understood that this was no longer about defense, but about raw power. Itachi, for his part, concentrated his chakra, channeling it into the seals with such precision that the air around him began to hum.
He broke off a fragment of rock and, with a silent jutsu, infused it with a tiny piece of metal. Then, he placed the projectile at the beginning of the line of seals.
"Get back," he said, and Renji took a few steps back, his eyes wide.
Itachi closed his eyes for a second, activating his jutsu for mental super-stimulation. His mind, now a hyper-analytical machine, calculated trajectories, vectors of force, and the exact amount of chakra needed for the impulse.
"This is not just a push," he thought. "It's a controlled railgun. A force that can break stone and pulverize bone."
When he opened his eyes, they glowed with a faint electrical charge. With a final seal of hands, he unleashed the chakra.
A deafening roar filled the courtyard. The projectile launched along the line with a screeching sound and a flash of light, hitting the large rock with such force that it exploded into a shower of dust and splinters, leaving a deep crater in the ground.
Fugaku, who had been observing from the shadows, appeared with a mixture of pride and dread. "Itachi," he said, his voice heavy. "That… what was that?"
Itachi looked at the dust cloud, his face impassive. "A more advanced application of chakra control, Father. The ability to manipulate forces and energy."
Fugaku nodded slowly, his Sharingan burning with the intensity of what he had just seen. He no longer saw a prodigy, but a force of nature in human form. The power was immense, but it was also a weapon that could destroy Konoha if it fell into the wrong hands.
"This," Itachi continued, his voice calm but firm, "is not just an attack. It's a way to demonstrate to our enemies that the Uchiha have more than fire and eyes. We have a power they cannot comprehend."
Fugaku understood. The boy no longer played at being a warrior; he was already thinking like one. And he was building his own arsenal, one with capabilities that could change the balance of power.
The father placed a hand on his son's shoulder. "This is too dangerous to show. To anyone. Not even to the elders. This power must remain a secret."
"I understand, Father," Itachi replied, though he was already thinking about his next experiment: a technique that would allow him to learn and execute jutsus with superhuman speed, using his mind as a supercomputer.
Meanwhile, Renji, on his own, had been developing the idea of magnetic control in a more subtle way. Using the same principle of the superconductor threads that Itachi had discovered, Renji designed a technique that didn't consume large amounts of chakra but required millimeter-precise control. His goal was to create energy pulses that could destabilize the enemy without needing a direct attack.
One afternoon, in the underground laboratory, Renji prepared for the test. In front of him, there was a small chakra generator that emitted a constant and controlled vibration. Beside him, Itachi watched in silence.
"The idea is to generate a wave, not a physical attack," Renji explained. "If I can make the chakra in the air vibrate at a specific frequency, I could interfere with an opponent's nervous system."
He concentrated chakra at the tips of his fingers, extending thin, invisible threads that dispersed throughout the room. With a subtle movement, he activated a low-frequency pulse. The chakra generator flickered and emitted an intermittent hum.
"It works," Renji whispered, excited. "The electromagnetic chakra pulse interferes with the generator's energy. If it were a ninja, their chakra system would be affected."
But he didn't stop there. Renji had gone further. He created another seal, much more complex, to generate sound waves that traveled through the chakra in the air. These waves, at a frequency inaudible to the human ear, had the potential to disorient and stun the enemy without leaving a visible trace.
Itachi watched him with fascination. It wasn't a flashy combat technique, but it was incredibly cunning. A way to nullify the opponent without them even realizing what was happening.
"Sound waves are like invisible ghosts," Itachi thought. "You can stun your enemy without them knowing what's happening. It's a perfect technique to face someone who relies on their senses."
Renji smiled, knowing that his work perfectly complemented Itachi's power. While Itachi built weapons of devastating power, he was creating tools of control and disorientation.
Itachi had spent weeks experimenting with chakra, electricity, and magnetic fields. But there was one detail he couldn't ignore: the brain in this world seemed to respond to chakra differently. Electrical stimulation could activate or accelerate certain areas, and he was determined to explore that phenomenon.
After several attempts, combining precise seals, controlled currents, and his understanding of chakra breathing, he managed to develop a unique jutsu: a technique that temporarily increased his brain capacity and his perception of chakra, functioning almost like a supercomputer inside his mind.
"If I activate this," he murmured, "I'll be able to learn any jutsu faster… and understand it from all angles."
When the technique was in use, Itachi could feel the flow of chakra with a precision that was previously impossible for him. Each movement, each thread of energy, each seal he drew acquired an incredible level of detail. Errors that had gone unnoticed before now appeared as "pending to be resolved," and he could analyze them from multiple perspectives: creative, strategic, and mathematical at the same time.
"It's like seeing the world with an infinite magnifying glass," he thought while adjusting a superconductor chakra thread. "Each detail matters, and I can anticipate how everything will react."
However, the technique had a limit. The electrical and mental load it generated on his brain was enormous. After using it, he needed to rest for an entire day to recover and be able to activate it again without risks.
Itachi decided to use it with caution, combining short periods of intense practice with rest. During those moments, his progress was exponential: he could perfect chakra control, understand new jutsu, and improve complex techniques like the magnetic shield or his experiments with electricity. Each session brought him closer to a complete mastery of energy flow and seal manipulation.
Renji watched from a distance, intrigued though unable to fully comprehend what he was seeing. To him, Itachi seemed almost invincible, capable of seeing what others can't and learning with incredible speed.
"Someday…" Itachi whispered as he closed his eyes to rest, "all of this will allow me to explore things no one has seen before… and to understand the deepest secrets of this world."