Sasuke followed Kakashi to a remote training ground.
This was Training Ground 3, surrounded by dense woods. In the center was an open clearing with a few training posts scattered on the ground.
"Alright, this should do."
Kakashi stopped, hands in his pockets, "Starting today, I'm your assigned Jonin Instructor. Pleased to meet you, Sasuke."
Sasuke looked around but didn't speak.
He had followed Kakashi here simply to see what this man could actually teach him.
"Well, before we start formal training, as your teacher, I need to understand my student's specific situation first." Kakashi took out a small notebook and pen from his Ninja Tool Pouch, adopting a posture of serious note-taking.
"First, you should be able to extract Chakra, right?"
Sasuke nodded.
As a member of the Uchiha Clan, this was something he had learned since childhood.
"Then, regarding Ninjutsu, which ones have you mastered?"
Sasuke frowned.
Ninjutsu.
The word sounded both familiar and strange to him.
Familiar, because it was the power he had pursued before.
Strange, because during those three years in the Soul Society, he had encountered a completely different power system… Reiatsu, Zanpakuto, Kido...
Compared to the Shinigami's concise and efficient power system, Ninjutsu, which required tedious hand seals and mobilizing Chakra inside the body, now seemed somewhat backward to him.
Fragmented memories flashed through his mind… scenes of his father, Uchiha Fugaku, teaching him before the night of the massacre.
"...Clone Technique, Body Replacement Technique, Transformation Technique." Sasuke recalled the basic three techniques taught at the Academy, spitting out the words somewhat stiffly.
"Mmhmm, the three basic techniques. A solid foundation."
Kakashi nodded, jotting it down in his notebook, "Anything else? Like the Fire Release your Uchiha Clan is best known for."
Sasuke fell silent.
'Fire Release?'
He seemed to know that.
But the problem was, he hadn't used it for a full three years.
After all, at the Shin'o Academy, Kido training was mandatory.
Whether it was Hadō for attacking by chanting incantations, or Bakudō for restraint and defense, he was quite proficient.
Kidō spells similar in nature to Fire Release, like 'Hadō #33, Sōkatsui', he could perform effortlessly, their power far surpassing ordinary Fire Release.
But Kakashi was asking about Ninjutsu.
That required hand seals.
He hadn't performed a single hand seal in three full years.
In the Soul Society, victory was determined by spiritual pressure strength, Zanjutsu, Hakuda, Shunpo, and the application of Kido.
Those tedious hand seal movements had long been forgotten.
"...A little." Sasuke finally gave an ambiguous answer.
Admitting he wasn't proficient in the Uchiha Clan's specialty was somewhat humiliating for him.
"A little is how much?"
Kakashi pressed, "For example, the Uchiha Clan's signature Ninjutsu, the Great Fireball Technique. Can you use it?"
"Yes."
"Good." Kakashi closed the notebook, "Then, for a more intuitive understanding, can you demonstrate it here? Just aim at that post over there."
He pointed at a post that looked relatively intact in the distance.
Sasuke glanced at him but didn't refuse.
He walked to the center of the clearing, facing the post dozens of meters away, and took a deep breath.
Then, he tried to recall those hand seal gestures forgotten in the corner of his mind.
Snake, Ram, Monkey, Boar...
Sasuke's fingers were somewhat stiff, his movements particularly clumsy.
It felt like asking a calligrapher to suddenly write with their feet… full of awkwardness.
Whoosh…
A burst of flame shot from his mouth, but it was less of a great fireball and more of a small flame.
The orange-red flame wobbled as it flew out, extinguishing weakly in the air before even reaching half the distance to the post.
The air instantly fell into an awkward silence.
In that instant, Kakashi even saw Sasuke's figure overlap with a certain old friend. His eye flickered, lost in thought.
Sasuke himself was also stunned.
He looked at his own 'masterpiece', a flash of astonishment in his eyes, followed by a surge of shame and anger.
'I, Uchiha Sasuke, a seated officer of the 11th Division, couldn't even properly use a basic Fire Release Ninjutsu?'
"Cough."
Kakashi broke the silence at the right moment. He walked over to Sasuke and patted his shoulder, using a comforting tone, "Don't worry about it. The first time is always like this. Maybe you were just too nervous."
His words sounded like comfort, but Sasuke could tell this guy was definitely holding back laughter.
"I wasn't nervous." Sasuke coldly shook off his hand.
"Alright, alright. Seems like you're just rusty from lack of practice."
Kakashi raised his hands in surrender, "But it's not a big problem. It just means there's a lot of room for improvement in your Chakra Control."
As he spoke, he pulled out a thin piece of paper from his Ninja Tool Pouch.
"Here, before we start formal training, let's do a little test first."
He handed the paper to Sasuke, "This is Chakra Test Paper. Infuse your Chakra into it, and it will tell you your Chakra Nature."
Sasuke took the paper. He did have some impression of this thing.
Chakra Nature.
It was key to determining what Ninjutsu a Shinobi could use.
The difference was, in the Soul Society, Reiatsu was just Reiatsu. It only had strength distinctions, no nature categories.
"How do I use it?" He asked proactively, for once.
"Simple. Just like before, concentrate and transfer your Chakra to the paper." Kakashi explained.
Sasuke did as instructed, channeling a strand of Chakra into the paper.
The next second, something miraculous happened.
The thin piece of paper was first instantly cut in half. One half crumpled into a ball, while the other half suddenly burst into flames.
"..."
"Lightning, Fire, Wind... and a few less obvious natures?" He looked at the changes in the paper, his expression somewhat complex.
"Sasuke, in your view, what is power?" Kakashi suddenly asked a strange question.
"A tool for revenge." Sasuke answered without hesitation.
"Just a tool?"
Kakashi shook his head, "You rely too much on that sword of yours and those strange techniques. You seem to have forgotten that the Uchiha Clan's greatest power comes from here."
He pointed to his own eyes, "The Sharingan is a mirror that reflects the heart..."
However, before he could finish, he saw three black tomoe slowly rotating in Sasuke's eyes.
'Three-tomoe Sharingan?! How is that possible?!' Kakashi was as if struck by lightning, frozen in place.
"Sasuke, your eyes..."
Sasuke remained silent, just calmly looking back at Kakashi with those three-tomoe Sharingan.
Then he suddenly retorted, "Didn't you say it? The Sharingan is a mirror that reflects the heart."
"Then, after witnessing the horrific scene of my entire clan being slaughtered, what do you think my heart would be reflected as?"