Konoha: Naruto, Taught by Aizen

Naruto, naturally, wouldn't refuse.

Chakra + Reiatsu + Senjutsu.

Naruto realized that his repertoire of trump cards seemed to be growing ever larger.

Within Naruto's psyche, Aizen was also intently watching everything unfold. To him, natural energy was an extremely foreign and fascinating type of energy. His curiosity about it was no less than his interest in chakra, perhaps even greater. Natural energy felt like an energy with properties diametrically opposed to Reiatsu. If I could master both and fuse them, Aizen mused, perhaps I could reach a new echelon of power. It was a promising idea, certainly worthy of extensive research. But does my own world even possess natural energy? A flicker in Aizen's eyes, he silently observed the unfolding events.

"Ordinary chakra is kneaded by balancing physical and spiritual energy. Senjutsu, on the other hand, involves drawing the natural energy from your surroundings into your body and then combining it with your own physical and spiritual energies in equilibrium." Lord Fukasaku began to explain Sage Chakra, Naruto sitting cross-legged on the ground, listening intently.

"Ninjutsu activated with Sage Chakra often possesses extremely destructive power."

"Our Mount Myoboku's Senjutsu is commonly known as the Frog Sage Arts. Sage Mode can typically be maintained for about five minutes. Come, Naruto, let's begin your initial Senjutsu training."

"Remember this carefully: you must remain calm and composed, your mind free of distracting thoughts. You also need to achieve a perfect 1:1 balance between your internal chakra and the natural energy. If you fail, your body could turn to stone, or worse, you could begin to frogify," Lord Fukasaku stated, his expression grave.

"I'll ask you one more time: are you absolutely sure you want to learn Senjutsu?"

Seeing Naruto nod, Lord Fukasaku took a deep breath and instructed Naruto to apply toad oil to his skin to better sense and absorb natural energy.

Jiraiya watched this scene, his nerves taut. Senjutsu training was exceedingly perilous. He himself had nearly died during his own training back in the day. Fortunately, he had managed to pull through in the end. Moreover, once Naruto succeeded, his combat strength could leap beyond that of a Jonin, possibly even breaking through to Kage-level. This would be a great boon for Konoha.

Under the guidance of the two Sages, Naruto gradually found his rhythm, his mind clear of distractions. Soon, the natural energy of the Summoning Realm began to surge towards Naruto. The speed of his cultivation was astonishing.

"Naruto is actually this sensitive to natural energy? His talent is truly formidable!" Even Lord Fukasaku, who had witnessed countless prodigies, had never seen a human cause such a violent stir in natural energy. The natural energy coalesced into a dense, white substance, continuously swirling around Naruto.

But then, bizarrely, an expression of agony twisted Naruto's face. Furthermore, the aura he exuded didn't resemble that of Senjutsu.

"Has the natural energy undergone an aberration?" Lord Fukasaku exclaimed, his voice betraying his shock. "What violent energy!"

The natural energy in mid-air began to rapidly transform into the type of energy the Sage had speculated might exist in the Pure Land, and it started to converge on Naruto's face. Simultaneously, Naruto's eyes suddenly turned bloodthirsty, filled with a dangerous glint. It was a terrifying gaze Jiraiya had never witnessed before. That imposing aura, that killing intent, sent shivers down the spines of all the toads on Mount Myoboku, striking fear into their hearts. Even Gamabunta arrived on the scene, warily keeping his distance.

"What's going on?" Jiraiya demanded, looking at the two Sages.

"The natural energy is being absorbed by Naruto's body, but it seems to have awakened something as well. Now, this natural energy is being… converted," Lord Fukasaku said, his face etched with apprehension. "I believe this might be a side effect of Naruto's Kekkei Genkai—the emergence of a negative persona! And now, this persona is trying to seize control of his main consciousness!"

"Is there anything we can do? Are we just going to stand by and watch?"

"No, we can't intervene. The chakra, natural energy, and that strange power within him are currently entangled, forming a delicate equilibrium. If we act rashly, we'll shatter that balance." Lord Fukasaku sighed heavily. "I think… all we can do now is wait."

When Naruto opened his eyes, he found himself unexpectedly within his Zanpakuto's inner world.

The palace was empty. The once brilliant, star-filled sky was gone, replaced by a swirling white mist that hung heavy in the air, looking viscous and repulsive. The atmosphere was thick with an endless chill and malice. And amidst the white mist, motes of light symbolizing natural energy still lingered. Naruto reached out, his hand passing through the natural energy, yet all he felt was an icy coldness.

"Kekeke…"

An intensely malevolent laugh suddenly echoed through the air. Then, a white shadow streaked across the sky, landing beside the throne.

"Is that… me?" Naruto focused his gaze, only to find that this white-robed figure possessed a face identical to his own, but the expression was warped with negativity, like that of a deranged lunatic.

"Kekeke, what disgusting energy." The White Shadow waved the white blade in its hand, and a large swathe of the thick white mist surged, engulfing the motes of light. He looked at Naruto, his expression sinister. "I'm finally back! Original body, from this moment on, I will replace you and become King!"

Under Naruto's bewildered gaze, the White Shadow moved to sit upon the throne.

However, the next moment, its body seemed to be struck by an immense force, sending it flying backward. Its chest and abdomen even caved in, and a white liquid sprayed from its mouth. It flew back at least thirty meters, tumbling and rolling until it landed at Naruto's feet.

It lifted its head, its face contorted with unbridled fury, and shrieked hysterically at the throne: "Why? Why won't you acknowledge me?! I'm clearly much stronger than this weak original! I am the King!"

But then, its gaze shifted to Naruto, a malicious grin spreading across its face. "I get it. As long as I kill the original body, I can become King." The white blade in its hand whistled through the air as it slashed viciously towards Naruto.

Naruto moved with a light step, instantly reappearing a hundred meters away, his expression impassive as he observed the White Shadow. Understanding had already dawned in his mind. This guy… this was his negative side, Hollow White. He had learned from Aizen that Shinigami and Hollows had a certain connection. Through special means, Shinigami could undergo Hollowfication, and Hollows could, in turn, gain Shinigami-like powers. And what he was facing now was the Hollow White, formed from his own negative emotions.

"A beast incapable of controlling its emotions," Naruto stated, drawing Kyoka Suigetsu, the blade humming softly.

This nonchalant posture further enraged Hollow White, who lunged at Naruto with all its might, blade arcing.

Clang!

The two blades met, erupting in a shower of violent sparks. Naruto felt a numbing sensation jolt up his arm, forcing him back a single step.

But Hollow White's second strike was already upon him, accompanied by a hysterical laugh. "You're too weak, original body! Why not let me take over? I'll destroy Konoha! I'll do a much better job than you!"

Naruto chuckled lightly, dodging the attack. He then lashed out with a reverse kick, striking Hollow White in the abdomen. In the next instant, he used Shunpo to appear behind Hollow White, Kyoka Suigetsu descending mercilessly.

"How is this possible?!" Hollow White, sent flying, had an expression of utter shock. It tensed its abdominal muscles, managing to parry Kyoka Suigetsu with its blade, but its own body slammed hard onto the ground.

Thud!

Naruto followed up by stepping firmly on Hollow White's face, a mocking expression on his own. "Trying to replace me? Is that the extent of your caliber?"