Aizen, a firm believer in science, was convinced that by delving into the essence of the Naruto world through scientific exploration, a path to the Six Paths level could be found. Here, in a universe dominated by chakra and bloodline powers, Aizen dared to speak of science. It seemed a far-fetched notion.
However, Aizen's thinking wasn't entirely unfounded. He had a logical framework supporting his theory.
The history of the Naruto world began with the arrival of two alien beings called Otsutsuki who sought to exploit the energy of the ninja world. They planted a divine tree to cultivate Chakra fruit. One of them, Kaguya Otsutsuki, betrayed her clan and consumed the Chakra fruit, giving birth to her sons, Hagoromo and Hamura Otsutsuki. This act disrupted the chakra flow within Kaguya.
Fearing a potential attack from the Otsutsuki clan, Kaguya unleashed the Infinite Tsukuyomi, a genjutsu that aimed to enslave the entire world and drain its chakra. This led to a clash between Kaguya and her sons, Hagoromo and Hamura.
Victorious, Hagoromo and Hamura sealed their mother on the moon and divided the chakra from the divine tree into nine parts, scattering them across the ninja world. These became the tailed beasts.
Years later, Kaguya's third son, Black Zetsu, emerged. Driven by the goal of reviving his mother, he manipulated the descendants of Hagoromo, including orchestrating the events of the Fourth Ninja War. He even tricked Madara Uchiha into reviving Kaguya through a sneak attack.
While Kaguya was eventually sealed again, the history of the Naruto world was undeniably one of scheming and manipulation.
This, in essence, was the underlying narrative of the Naruto world: a story of harvesting and accumulating power.
The second key concept in the Naruto world revolved around the completion and competition of bloodline traits, the most prominent examples being the Sharingan and Byakugan.
The Sharingan could evolve into the Mangekyo Sharingan, granting even greater abilities. However, overuse of the Mangekyo Sharingan carried the risk of blindness. There were two known solutions:
Transplanting a sibling's Mangekyo Sharingan to create an Eternal Mangekyo Sharingan, offering superior power without the risk of blindness.
Transplanting cells from Senju Hashirama, the First Hokage, which significantly reduced the blindness caused by using the Mangekyo Sharingan.
In the original Naruto series, characters like Madara Uchiha and Sasuke Uchiha employed the first method, while Obito Uchiha used the second.
Aizen theorized that the risks associated with the Mangekyo Sharingan were akin to a genetic disease. By supplementing the defective genes, this condition could be rectified, potentially even leading to an evolutionary leap beyond the original form.
The evolution of the Rinnegan, which required possessing the Eternal Mangekyo Sharingan and transplanting Senju Hashirama's cells, further solidified this theory for Aizen.
The Byakugan's evolution, on the other hand, seemed more straightforward.
Aizen's belief in science extended beyond the Soul Society. In the Naruto world, the Otsutsuki clan on the moon ruthlessly eliminated their own branch members, stealing their Byakugan and genetic material. This act not only resulted in the creation of the Tenseigan, a powerful dojutsu, but also birthed the Otsutsuki descendants with almost pure Hamura Otsutsuki blood. Furthermore, transplanting the Byakugan of Hyuga Hanabi, a prodigy, into one of these descendants directly triggered the evolution of a Tenseigan rivaling the Rinnegan.
This, according to Aizen, underscored the fact that the entire Naruto world revolved around a relentless pursuit of power through energy and bloodline manipulation. He argued that this principle wasn't unique to Naruto; it held true for the Soul Society as well.
The Hogyoku served as the prime example in Bleach. The Hogyoku was said to unlock a being's potential. However, examining its creation process revealed otherwise.
One-half of the Hogyoku originated from hundreds of deceased Soul Reapers or those with latent Soul Reaper abilities. The other half was crafted by Urahara Kisuke using vast quantities of Hollow material. Merging these two halves yielded the ultimate Hogyoku, capable of blurring the lines between Soul Reapers and Hollows.
It's important to note that these raw materials weren't chosen randomly. For instance, Matsumoto Rangiku's spiritual power contained fragments of the Soul King, the supreme ruler of the Soul Society.
So, the supposed transcendence achieved via the Hogyoku was essentially a fusion of Soul Reaper and Hollow power – a combination of energies and a genetic evolution. The transformation triggered by the Hogyoku manifested directly in the creation of Vizard, beings who were both Hollow and Soul Reaper. This had little to do with unlocking one's inherent potential.
And why was Ichigo Kurosaki so formidable in his Soul Reaper form? It wasn't simply because he possessed the powers of a Soul Reaper, Hollow, and Quincy simultaneously. The sheer volume of power he wielded surpassed even Aizen, who'd transcended the boundaries of Soul Reaper and Hollow. This provided a logical explanation for Ichigo's eventual victory.
The Key to Power: Beyond Bloodlines
Aizen concluded that achieving the Six Paths level required a "plug-in," akin to the Hogyoku, that could continuously integrate high-level energy and bloodlines. In simpler terms, an external power source was necessary.
But was there a way to defy fate without relying on plot armor? Aizen believed there was – by creating his own "plug-in."
And the key to building this plug-in? Science!
This was Aizen's answer. Through studying medical ninjutsu, he aimed to understand the chakra-based biological system in the Naruto world. He combined this knowledge with his vast biological expertise from his previous life as Aizen Sosuke, a Soul Reaper, and the scientific knowledge of his current world.
Aizen was confident that with time, he could create their own "plug-in" to surpass bloodline limitations.
Reassured by his plan, Aizen settled down in the mostly empty medical room to delve into the world of ninja biology. Since mastering medical ninjutsu required a particular aptitude and was a relatively tedious pursuit compared to flashy combat techniques, few students opted for it. This, of course, contributed to the scarcity and value of medical ninjas.
The explanation for why Konoha's leadership in the original Naruto series disagreed with Tsunade's proposal was clear. Without any concrete evidence or experimentation, sending low-powered but invaluable medical ninjas to the frontlines was a gamble no qualified leader would take.
As time flew by, it was soon afternoon...
Aizen slowly closed the medical ninjutsu textbook and exhaled softly. Placing the book back, he headed towards the ninja academy training grounds...
The training ground was already bustling with activity, countless boys and girls fueled by youthful enthusiasm.
The moment Aizen stepped onto the grounds, a familiar figure caught his eye – Minato Namikaze, waving him over. Beside him stood a young man in a dark blue uniform with a fan pattern on his back. This handsome young man bore a striking resemblance to the Uchiha prodigy recently introduced in the story.