Over the next few weeks, Minato devoted all his time to teaching Shisui and Itachi the secrets of his spatial jutsu. The Hokage's discipline was strict but effective; every movement, every chakra estimate, and every directional calculation were constantly corrected and perfected.
Itachi, for his part, already had a basic grasp of teleportation, though he still needed a few moments to precisely calculate the direction before executing the jutsu. His prodigious mind could integrate information from the seals and the geometry of space, but each use demanded exact concentration and coordination.
Shisui, in contrast, was advancing more slowly. His chakra control wasn't yet on par with Itachi's, and he had to internalize the complex formulas needed for teleportation. These formulas consisted of a set of mathematical matrices that, by estimating the correct direction, established a connection between the origin and destination seals. Each teleportation required mentally tracing a straight line through space—a line that had to perfectly align with the seal's energy and chakra flow for the technique to be precise and safe.
Minato insisted on the importance of understanding the concept behind the technique, not just memorizing the seals. "It's not just about moving the body from one point to another," the Hokage would say. "You must calculate the trajectory, feel the energy of the environment, and ensure that the line you draw in space matches the seals. If a single element fails, the jutsu could be dangerous."
Itachi absorbed every word and every demonstration, practicing over and over, adjusting the speed of his teleportation and the stability of his movements. Shisui watched him, copying every gesture, every adjustment in posture and chakra pressure, trying to internalize the combination of technique, calculation, and sensation.
As the days passed, the difference between them became clear: while Itachi could quickly calculate the line and perform the teleportation almost instantly, Shisui still had to concentrate on mentally tracing the line and coordinating the chakra flow, so each jutsu took him more time and energy.
Nevertheless, Minato acknowledged the talent of both. "Itachi has the advantage of speed and precision," the Hokage commented, "but Shisui is developing the deep understanding of chakra that's needed. With time and practice, both of you will be able to execute complex teleportations without error."
This training not only strengthened their individual skills but also taught them to synchronize their jutsus and anticipate movements together, laying the groundwork for much more advanced strategies in the future.
These weekly training sessions with Minato were held in secret. The Hokage always left a clone at the main building to watch over the village and ensure no information was leaked. No one was to know that a six-year-old child, along with Shisui and Fugaku, was being trained in advanced teleportation and chakra manipulation techniques.
At the same time, Fugaku, Itachi, and Minato began preparing a specific plan to protect Kushina during the birth of her son. The priority was to ensure that no surprise attack could reach her, and the threat of Madara made a strategic and multi-dimensional approach essential.
Kushina would give birth in an isolated location at the back of Konoha, a protected area away from the village's usual traffic. This allowed for stricter security measures and minimized any risk. Fugaku coordinated the placement of different Uchiha units around the area, ensuring they were alert and ready to immediately report any anomalies. Each soldier had precise instructions on patrols, strategic positions, and alert protocols.
Fugaku brought the full might of the Uchiha clan to bear. His automatic turrets, capable of detecting the slightest movement, were strategically placed around the birthing location. Each device was connected to a rapid alert system and could fire accelerated chakra bullets, thanks to Fugaku's chakra control. This ensured that any intruder would be neutralized before they could get close.
"Hokage," Fugaku commented to Minato while adjusting the turret settings, "there's a detail you should know: it seems Madara possesses a spatial jutsu that allows him to become intangible and pass through solid objects. Any direct physical confrontation would be complicated."
Minato frowned, evaluating the information. "That complicates everything. But at the same time, it gives us an advantage: if we know the limitations of his jutsu, we can better prepare to neutralize him or anticipate his movements."
Furthermore, Fugaku was ready to intervene directly. His Mangekyō Sharingan granted him access to Amaterasu, and although they couldn't be sure of its effectiveness against an adversary like Madara, the black flames would be a powerful deterrent. And if the situation reached a critical point, Fugaku had the ability to deploy his Susanoo, even in Sage Mode, which would provide an extremely superior defense and counterattack.
"It's not just about protecting Kushina," Fugaku said. "We also need to train our coordination with you, Minato. If we have to face an enemy who can become intangible, perfect synchronization between offense and defense will be key."
Minato nodded. "Exactly. Once I manage to place a seal on him, we'll have the advantage that I can get to him at any time. If you can do the same, that would be for the best."
Itachi nodded and thought of another idea. "If you can place a seal on him, you could also transport a bomb to his position, or we could try to create a spatial seal to block his movements."
Minato's eyes lit up, and he nodded in agreement. He then set out to search for a spatial seal with Kushina; the Uzumaki clan had many seals, and perhaps one of them would be useful.
The improvised training ground on the outskirts of Konoha was filled with scrolls, seal marks, and devices that could barely be compared to conventional weapons. Minato and Kushina had dedicated days to studying and testing spatial seals that could immobilize a target without needing a physical confrontation. Each line drawn with chakra had to be precisely calculated, considering both the energy flow and the structure of the surrounding space.
Meanwhile, Itachi worked in his portable laboratory, focused on a new invention: small bombs that exploded after a few seconds, similar to grenades. Each unit was calibrated to release condensed chakra upon detonation, creating a devastating yet controlled effect. Itachi tested the timers and the range of action, ensuring that the power was not underestimated, and at the same time, that its use could be integrated with the spatial seals Minato was perfecting.
Although he knew that explosive tags, a common ninja item, existed, the bombs Itachi was working on had more advanced features, such as a concealment function, explosions that integrated the nature of chakra, and he even considered including poison attacks, but he did not want anyone to get harmed by them.
"If we place these devices alongside the seals, we could neutralize the enemy before they even realize it," Itachi commented while adjusting the chakra flow of the explosion. "It's not about causing unnecessary destruction but about maximizing efficiency."
Minato nodded, observing how the explosion patterns of Itachi's bombs synchronized with the spatial seals he had prepared. "Exactly," he said. "The combination of immobilization and controlled attack is what can keep Kushina safe. And if we need to, we can use teleportation to relocate both the devices and the targets in real-time."
Kushina, watching the boys work, couldn't help but smile with pride and a touch of disbelief. "I never thought I'd see something like this," she said. "You're preparing a level of defense that could rival any military strategy."
Itachi fell silent for a moment, contemplating the diagrams of the seals and the bomb tests. Each trial not only perfected his invention but also taught him how to manipulate chakra with pinpoint precision for tactical objectives. Even small variations in the explosive power could mean the difference between neutralizing a threat or causing a failure in their defense.
"We must also consider synchronization," added Shisui, who had joined the tests. "It's useless to place the bomb and the seal if their activation times don't match."
"Exactly," Itachi replied. "We can program a chain of events: the seals act first to immobilize, then the detonation controls the area, and, if necessary, teleportation can redistribute the effects."
The group worked for hours, testing combinations, adjusting timings, and studying the interaction between spatial jutsus and attack devices. Each trial allowed them to better understand the possibilities of advanced ninja technology and the strategic application of chakra, preparing the ground to protect Kushina safely and efficiently, without relying solely on brute force.