Deep within the Land of Demons, inside the Priestess's Palace.
The current Priestess, Miroku, stood with a grave expression, blocking the entrance to the underground sealed location. "The demon threatening the world is sealed here! It must absolutely not be opened! Please, both of you, leave at once!"
Miroku emanated pure spiritual power, trying to stop them. However, against the absolute gap in power, her resistance seemed so feeble. With just a look from Sasuke, Miroku was knocked unconscious. Fortunately, neither of the two were interested in women... they calmly stepped over her.
In the center of the underground palace was an ancient altar. Sasuke casually broke the altar, and a mass of constantly twisting, dark purple mist-like spiritual entity, exuding intense ominousness and resentment, flew out. "Hahaha! I'm finally free! Foolish humans, you dared to release me! I will devour your souls, I will bring this world..."
Its mad laughter stopped abruptly. A semi-transparent hand appeared out of thin air, grabbing the demon like a bothersome fly.
'Truly powerful,' Orochimaru marveled inwardly. No matter how many times he saw it, he was amazed by this deity's power.
Setsuna utilized the 'culinary skills' he learned in the Soul Society. Fingertips shimmering with dark gold light, with a few kneads, separations, and refinements, the soul of the demon, filled with resentment and impurities, was purified and transformed into a mass of soul light clusters emitting an enticing fragrance.
"Eat it," Setsuna said, handing the light cluster to Sasuke and Orochimaru.
Although it was made from a disgusting demon, Sasuke swallowed it without any hesitation. The light cluster entered his body, transforming into a stream of warm, pure energy that nourished the origin of his soul, rapidly spreading to every corner of his soul.
He immediately felt that the soul pain caused by six months of Baryon Mode training was greatly alleviated. His mental strength became more condensed, even his thinking seemed slightly faster.
After consuming his share, Orochimaru's whole body trembled. He incredulously raised his bandaged, atrophied, deformed hands. He could feel the souls of his hands, which had been devoured by the Dead Demon Consuming Seal, beginning to be reshaped.
"Thank you... Great One!" Orochimaru's voice trembled with excitement. The hands he had always wanted to heal were being restored so easily.
"No need." Setsuna looked at him. "Next, I need your help with a small matter. Summon your summoning creature, Manda."
Orochimaru was puzzled but complied with the hand seals: "Summoning Technique!"
Bang!
Manda, massive as a mountain and radiating terrifying ferocity, appeared, barely fitting within the underground palace. It impatiently flicked its tongue: "Orochimaru, what is it this time? If there aren't enough sacrifices, I'll..."
It didn't finish its sentence. Because Setsuna, simply facing it, made a grasping motion in the air from a distance. Manda's colossal body was instantly compressed as if by an invisible giant hand. It didn't even have time to scream before, under Orochimaru and Sasuke's stunned gazes, it transformed into two translucent, shimmering meatballs, exuding rich life essence and pure Natural Energy.
"Sasuke's body is severely depleted and needs a major tonic," Setsuna stated matter-of-factly. "Manda's life essence and Natural Energy are just right. Eat it."
Sasuke picked up the meatball in front of him and swallowed it in a few bites like a large pill. The surging, unimaginable life energy and pure Natural Energy rushed into his limbs and bones. His life force, riddled with holes and nearly exhausted from radiation and depletion, was like parched earth welcoming a rainstorm, frantically absorbing, repairing, and growing.
The feeling of being comprehensively fulfilled and strengthened, from soul to body, made him let out a comfortable groan.
"Manda, you died such a pathetic death!" Orochimaru silently took a bite of Manda's meat, couldn't help but exclaim, "But you're so delicious!"
...
Time passed... another six months went by. After the 'major tonic' in the Land of Demons, Sasuke continued training under Setsuna. His aura grew more restrained and deeper, but the occasional leak of a hint of sharpness made even Orochimaru feel a sense of fear and unease.
One day, based on intelligence, Sasuke finally found the person he had been thinking about and hating for so long in a remote valley… Uchiha Itachi.
Itachi seemed to have anticipated his arrival, standing alone in the center of the valley, wearing the black and red cloak of the Akatsuki, his eyes complex as he watched Sasuke approach step by step.
"Sasuke..." Itachi's voice was slightly hoarse.
"Uchiha Itachi." Sasuke stopped, facing him ten meters apart, his voice eerily calm. "I already know everything. I know the truth about the massacre, know the choices you made to protect me."
Hearing this, Itachi's heart trembled slightly... he couldn't maintain his aloofness.
Yet, Sasuke's tone remained icy: "You might think that after knowing this so-called truth, I would forgive you, would appreciate everything you did for me? But it's precisely because I know this truth that I find you even more repulsive!"
Itachi's body stiffened suddenly.
"What right do you have to arrange my life?" Sasuke stepped forward, his presence imposing. "What right did you have to take the lives of the entire clan? Among those clansmen were elderly, children, women… ordinary, common people. But you, you killed them all for my sake. Because of you, I carry an unimaginable sin. My very existence is the original sin... living is the greatest pain!"
Itachi's face paled slightly... he seemed to realize he had indeed been somewhat self-righteous.
Sasuke continued: "Even in the darkest, bloodiest Warring States Period, few would commit such a heinous act as 'massacring one's own clan'! And you... you did it! Your existence is the greatest darkness in the Ninja World! Darker than any demon, any war!"
Itachi opened his mouth to defend himself, but found his throat dry, unable to produce sound.
"Sasuke, is that how you see me?" He finally asked bitterly, his voice filled with exhaustion and confusion.
"Yes," Sasuke nodded, his eyes sharp as knives. "I admit, I used to admire you. I thought graduating from the Ninja Academy at seven was impressive, that you were a genius. But looking at it now, you're nothing but an illiterate who never received a proper education! Your shallow insight, your narrow perspective, your self-righteous 'greater good'… you simply can't contemplate such grand concepts as 'peace and sacrifice'! In the end, you're just a fool flattered and elevated by Konoha's elders, by the so-called Will of Fire, pretending to be mysterious, unknowingly used by others!"
Itachi staggered back a step as if struck by lightning. Sasuke's words, like the most merciless scalpel, had precisely dissected the cornerstone upon which he had always supported his own convictions.