Naruto: Aizen's Shadow in Konoha

Beside a creek in Konohagakure's eastern outskirts, Aizen stood with hands clasped and mouth open. A thin stream of high-pressure water erupted from his mouth, sputtering rapidly.

The sharp water jets resembled lasers. In a few bursts, the large trees across the stream sliced through like butter under a hot knife, disintegrating with a dusty blast.

"Whew!" Aizen bent down, panting, a few beads of sweat trailing down his cheeks.

The clear water reflected his current appearance. A handsome face with sharp features, brown hair, and brown eyes held a hint of future attractiveness even at this young age.

He sported a black training suit similar to a Shinigami's Shihakusho, his hair styled in the same three-seventh part as Shinigami Aizen in his early appearances. Plus, perched on his face were a pair of black-rimmed glasses, a look he adopted later on.

This was essentially a teenage Aizen, untainted by his future betrayal of Soul Society. The loose material of the training suit offered better flexibility for swordsmanship practice, and the glasses were purely for creating a gentle, harmless facade – perfect for fostering a deceptive persona.

After all, who would suspect a well-mannered, handsome guy with glasses of harboring such cunning intentions?

That inspiration, too, stemmed from the memories of Shinigami Aizen Sousuke.

As he understood it, Shinigami Aizen Sōsuke, during his manipulative years in Soul Society, meticulously crafted his own demeanor and personality.

Whether it was the gentle and refined temperament or the image of a courteous elder, he cultivated a persona that garnered favor from most people. At the very least, it evoked little animosity.

One could say Shinigami Aizen Sōsuke truly grasped the essence of "deception." After all, how else could someone remain undetected in Soul Society for centuries?

With such a masterful role model before him, how could Aizen not learn a thing or two?

"I never anticipated the original owner's talent to be so exceptional. Even a high-level B-rank jutsu like Water Severing Wave can be mastered so quickly. My previous assessment was clearly wrong."

Leaning back slightly, Aizen recovered his composure and nodded with satisfaction as he surveyed the ravaged landscape across the river.

Based on his estimations and the innate abilities this body displayed today, Aizen wasn't convinced it was any less talented than Namikaze Minato himself!

Initially, Aizen attributed this sudden surge in talent to the enhancement his soul received from transmigration.

Admittedly, that was a contributing factor. Aizen's performance in terms of perception and reflexes was particularly outstanding. However, it wasn't the sole explanation.

Later, Aizen discovered his initial guess was woefully inaccurate. Through a thorough examination of the original owner's memories, he learned that the boy's mother had subjected him to rigorous physical training during his youth. This rigorous regimen resulted in exceptional physical fitness far exceeding his peers.

Whether it was raw strength, recovery speed, or the rapid improvement in overall physical conditioning, the original owner could be considered a prodigy. It was only due to his parents' deaths that the training ceased.

However, even with that interruption, the original owner, relying solely on the basic ninja knowledge acquired at the academy, managed to defeat the Sarutobi clan's offspring, the Sarutobi siblings, with just three punches and two kicks. This feat further solidified the notion of his terrifying talent.

Now, Aizen was simply unlocking the potential that already resided within the original owner. Coupled with the fusion of his own battle-hardened soul, the resulting talent could very well be described as monstrous.

"For now, I'll put ninjutsu practice on hold. As a pre-Academy student, I can barely handle B-rank jutsu. The next focus will be on honing my perception and swordsmanship skills," Aizen decided, lowering my head in contemplation.

Unlike chakra refinement, which could be practiced anywhere, jutsu requiring vast open spaces were necessary for proper training. Aizen chakra possessed three elemental affinities: earth, fire, and water. Water was demonstrably his strongest element, followed by earth, with fire being the weakest.

Over the past few days, Aizen concentrated on Water Style techniques. Currently, he mastered three jutsu: Water Style: Water Severing Wave, Water Style: Water Wall, and Water Style: Water Rush.

Additionally, he mastered two Earth Style techniques: Earth Style: Hiding in Ground Jutsu and Fire Style: Great Fireball Jutsu.

Naturally, Aizen hadn't neglected the fundamental Three Body Technique and the art of throwing hidden weapons. The Body Replacement Technique, in particular, held special attention. Even in battles between Kage-level powerhouses, as depicted in the original work, this technique remained surprisingly prevalent.

Clang!

A metallic clang resonated through the air.

Aizen slowly drew a sharp black sword from the sheath strapped to his waist. This wasn't Kyoka Suigetsu. Aizen's eight-year-old body couldn't wield it effectively. Instead, he'd procured a custom-made black katana from a ninja shop. It was a third shorter than a standard katana to better suit his stature.

Kyoka Suigetsu, on the other hand, resided within his consciousness, ready to be summoned at a moment's notice. Perhaps this was an unforeseen benefit bestowed by the system.

Now, the reason for practicing with a blade… well, that tied back to Shinigami Aizen's strongest ability.

If you asked about Aizen Sosuke's most potent skill in Soul Society, you'd get a variety of answers. Some might say Kyoka Suigetsu, others Kido, and some would undoubtedly argue for Reiatsu!

But Aizen, inheriting these memories, would definitively answer – Kenjutsu!

Hakuda (hand-to-hand combat) and Hoho (high-speed movement) were just two of the four fundamental Shinigami combat skills. While the elegant Shihakubo (swordsmanship), the elusive Shunpo (flash step), and the flashy Kido (demonic arts) all saw frequent use amongst Shinigami, only Kenjutsu, the first of these core skills, remained largely unseen.

Apart from Unohana Retsu and Zaraki Kenpachi, Aizen Sosuke was the only Shinigami who utilized it with such prominence. The sheer shock he caused by effortlessly knocking out a captain with Kyoka Suigetsu in his first attack was unparalleled. Not to mention the now-legendary scene where he faced another captain with just his sword, leaving his comrades utterly speechless.

Sunlight glinted off the blade, reflecting a bright light onto Aizen's glasses. This, in turn, illuminated his eyes, which had been somewhat obscured by the lenses.

Aizen's light brown eyes were captivating. They resembled a clear lake – gentle, delicate, and pure. One could almost see a sincere and kind soul reflected within them.

However, beneath this seemingly calm lake lurked a torrent of hidden currents, brimming with danger. This deceptive facade stood in stark contrast to the tranquil surface.

It was an enigma, an illusion.

Aizen ran his hand along the blade, a resolute glint in his eyes. He took Kenjutsu far more seriously than even Kyoka Suigetsu.

Only those who had inherited all of Aizen Sosuke's memories could truly comprehend the terrifying power of Kenjutsu!