Sasuke walked to the tree and spoke coldly, "It's not about using more chakra, idiot. Imagine it as a thin film, not too much, not too little, just enough to stick to the soles of your feet."
Before his voice had even faded, he had already walked up the tree trunk with ease. He then leaped down from the tree, the entire process taking no more than three seconds.
"Understand?" he glanced at the gaping Naruto beside him.
"Oh... oh, I get it!" Naruto came back to his senses and nodded vigorously.
He imitated Sasuke's movements, closing his eyes to concentrate, and then stomped his foot hard against the tree.
Thud!
The result was predictable. The bark shattered, and Naruto was sent flying once again.
Sasuke watched this scene, his brows knitting even tighter.
He snapped impatiently, "Moron, I told you not to use brute force, but to attach the chakra to your feet!"
"I know, but it won't listen to me!" Naruto was on the verge of tears. He felt like the chakra inside his body was a tangled mess.
"Won't listen?" Sasuke frowned.
Chakra was a combination of a ninja's physical and spiritual energy. How could it 'not listen'?
Unless his control was abysmal, but this guy's perseverance and physical abilities were clearly strong...
In Sasuke's eyes, the three-tomoe Sharingan appeared once more.
He wanted to see for himself whether this idiot was incompetent, or if there was some other reason.
As the Sharingan spun, the chaotic flow of chakra within Naruto's body became clear.
"Something's wrong..." Sasuke's brows locked even tighter. He pushed his insight to its absolute limit.
Then, he saw the source of the problem, and his pupils contracted suddenly.
He saw that within Naruto's body, surrounding his own blue chakra, was another, completely different red chakra.
It was filled with a tyrannical and ominous aura.
Whenever Naruto tried to gather his blue chakra, the red chakra would forcefully tear at it, interfering with his own.
"What is this?"
Sasuke felt a strange familiarity in this chakra, which was filled with malice and hatred.
It was like the "Hollows" he had slain.
"I see..." Sasuke instantly understood the root of Naruto's failure.
This wasn't a simple matter of control. There was something else dwelling inside this guy.
"Hey, idiot."
Sasuke's expression became a little grave. "You, hold out your hand."
He wanted to confirm what that red thing was.
Sasuke closed his eyes and channeled his spiritual power through his hand.
The moment his spiritual power made contact with Naruto.
His consciousness was suddenly pulled with great force, as if a deep pit had opened up beneath him, and he was falling into weightlessness.
When he came to his senses.
He was in a damp, dark sewer.
It was filled with an aura of decay and hatred.
Where is this?
Sasuke looked around and felt a familiar power. It was the same power that interfered with Naruto when he tried to gather chakra.
This must be Naruto's inner world.
But... what is the source?
Sasuke stood up and followed the trail of the aura, walking down the path.
He soon reached the end.
A towering, giant red barred gate blocked his path. It was dark behind the gate, as if something was dwelling there.
Heavy breathing and undisguised malice continuously seeped out from between the bars.
It seems this is the source of the energy.
"Hey, brat," the enormous crimson creature behind the gate sensed the movement and called out.
Sasuke followed the voice and walked forward.
With a whoosh, a giant claw shot out with a gust of wind.
Clang! It slammed hard against the gate, the long tips of its claws piercing through the gaps, stopping just a hair's breadth from his throat.
"You've got some nerve, brat, not even trying to dodge."
"Heh."
Uchiha Sasuke snorted coldly, raised his head, and stared at the Nine-Tails with his Sharingan.
"Just a bit of leaked energy. In the end, you're nothing more than a beast locked in a cage."
"What did you say?!" The Nine-Tails instantly flew into a rage, its massive body slamming against the bars.
A dark shadow loomed over him as a giant face pressed against the gate.
It was a fox, with slanted, triangular eyes.
When it saw Sasuke's eyes, the hatred in its own eyes almost materialized.
It bared its teeth, a menacing maw full of sharp fangs. "It's these damn Sharingan eyes again! You Uchiha clan, what else can you do besides using these eyes to control others?!"
"Control?"
Sasuke frowned, slightly puzzled.
The Nine-Tails snorted and pulled its head back.
It didn't explain, nor did it want to continue mentioning those Mangekyo Sharingan eyes.
As the strongest of the Tailed Beasts, even though it was now sealed within someone else's body, it still had its dignity.
Being controlled... it was too embarrassing to talk about...
Looking at the giant beast before him, Sasuke seemed to think of something. "I've heard a rumor since I was a child, that the Fourth Hokage saved the village from a demon fox."
His tone was certain. "In that case, you must be that demon fox."
The Nine-Tails grinned, showing no shame. "So what if I am? You humans only know how to call me that."
Sasuke's heart sank.
He instantly understood why Naruto was looked at with such eyes by the villagers, why he was hated by everyone.
Because this demon fox was sealed inside him.
But in the village rumors, he had become the embodiment of the disaster that destroyed the village. That was interesting.
Sasuke's thoughts raced, and he suddenly remembered the words the Nine-Tails had blurted out earlier—
"besides using these eyes to control others."
Control?
A terrible thought formed in his mind.
Sasuke looked up, his Sharingan locked onto the Nine-Tails. "The Demon Fox Rampage seven years ago... you were being controlled by a Sharingan then, weren't you?"
"Nonsense!"
The Nine-Tails bristled like a cat whose tail had been stepped on. "I am the strongest Tailed Beast in the world! How could I be controlled by a mere human's dōjutsu!"
The more vehemently it denied it, the more certain Sasuke became of his guess.
The Demon Fox Rampage was not a natural disaster, but a man-made one.
It was someone with a Sharingan who had orchestrated everything from behind the scenes.
Who could it be?
"Who was that person?" Sasuke's voice became incredibly cold.
Among the Uchiha clan, someone with such powerful dōjutsu, capable of controlling this demon fox...
The first figure that came to his mind was that man.
But he quickly dismissed the thought.
No, the timing doesn't add up.
The Demon Fox Rampage happened seven years ago. At that time, Itachi was only five or six years old. Even if he was a genius, it was impossible for him to have the power to control the demon fox.
Then, besides Itachi, who else could it be?
In the village, there was another non-Uchiha who possessed a Sharingan, Hatake Kakashi?
No, that's even more impossible.
Kakashi's eye was a transplant; it couldn't unleash the true power of the Uchiha bloodline.
Then, who could it be...