The hot spring town of Niji Rainbow Spring Yu, located on the border of the Land of Hot Water Springs, was shrouded in twilight. Lanterns along the streets lit up one by one, casting warm halos in the steamy air. Jiraiya and stood up from the open-air hot spring, water droplets sliding down his muscular physique.
"Ah--this is life!" He sighed contentedly, wrapped himself in a bathrobe, and walked towards the changing room in his wooden clogs.
From the women's bath next door came Karin's scream and the sound of splashing water, "Naruto! You're dead if you dare use Shadow Clones to peek!"
"I didn't!" Naruto's aggrieved voice rang out. "It was that Pervy Sage who said he was going to collect writing material..."
Jiraiya chuckled twice and quickly slipped out of the hot spring area. He went to the inn's lobby, ordered a pot of sake, and sat alone under the eaves to sip it. The afterglow of the setting sun draped the town in a light orange veil, and steam rose from several hot springs in the distance, like the white breath exhaled by the earth.
"Lord Jiraiya." Karin's voice came from behind. She had changed into casual clothes, her wet red hair draped over her shoulders. "I sensed a strange Chakra in the hot spring just now... It was the Sound Ninja I sensed on the way, but it was different."
Jiraiya's sake cup hovered in mid-air. "Oh? The exact location?"
"It's about six miles west of the town." Karin adjusted her glasses. "Her Chakra was very subtle, intermittent, as if she was deliberately concealing it."
Jiraiya nodded and downed his drink in one gulp. "You and Naruto stay at the inn, I'll go check on things."
"Not again!" Naruto was already standing at the end of the corridor, his blond hair still dripping wet. "You always leave me behind when you're on a mission! I'm not a child anymore!"
Jiraiya walked over and vigorously ruffled Naruto's hair. "It's precisely because you've become stronger that you need to stay here to protect Karin." He lowered his voice, "What if this is a diversionary tactic?"
Naruto opened his mouth, but finally muttered reluctantly, "Okay, okay..."
"Karin, stay alert." Jiraiya tightened his Forehead Protector. "Notify me immediately with a flare if anything seems amiss."
Karin nodded earnestly. "Understood."
Jiraiya formed a hand seal and vanished instantly. Naruto stared at the empty corridor, his fists clenching involuntarily.
"Hey, Karin," he suddenly spoke, "Are we really just going to wait here like this?"
Karin looked at him warily. "What do you want to do? Lord Jiraiya said—"
"That Pervy Sage is always like this!" Naruto interrupted her. "I'm capable of handling things on my own now..." His blue eyes flashed with resentment. "Sasuke is probably nearby, while I can only soak in the hot springs!"
Naruto's eyes suddenly lit up. "Let's go, we'll follow the Pervy Sage!" He turned and ran towards the room, "I'm going to get my ninja tool bag!"
Karin wanted to stop him, but her outstretched hand froze in mid-air. She understood Naruto's feelings...
"Wait for me," she finally said, "My senses can help."
Meanwhile, Jiraiya had tracked the trail to the edge of the forest west of the town. Night was falling, and the mist in the forest mixed with the steam from the hot springs, making visibility extremely low. He crouched on a tree, his hands forming a hand seal.
"Ninja Art: Toad Detection Technique"
A subtle fluctuation of Chakra emanated from his palm, rippling across the entire forest. A few seconds later, he opened his eyes. "Found it."
Deep in the forest, a figure wearing Sound Ninja vest was moving quickly towards an abandoned mine. The person moved furtively, glancing back frequently, clearly carrying out some kind of secret mission.
Jiraiya followed silently, maintaining a safe distance. The Sound Ninja arrived at the mine entrance, cautiously forming several hand seals. The Genjutsu Barrier at the entrance briefly dissipated, revealing a downward staircase.
"Something's definitely fishy..." Jiraiya narrowed his eyes, and after the Sound Ninja entered, he slipped in like a gust of wind.
The interior of the mine had been converted into a makeshift base, with torches stuck in the walls to illuminate the damp passageway. Jiraiya moved forward close to the wall, catching the sounds of rummaging through drawers and the crackling of burning paper coming from ahead.
"Destroying evidence?" A thought flashed through his mind, and he quickened his pace.
After turning a corner, the view suddenly opened up—a laboratory of about fifty square meters appeared before them. The Sound Ninja was busy throwing documents into the central brazier, and various instruments and test tubes were scattered on the experimental table next to him.
"Good evening," Jiraiya lazily, leaning against the doorframe. "Would you like me to boil some water for tea?"
The Sound Ninja whirled around, a look of horror flashing across his face. Almost instinctively, he threw three Shuriken and leaped backward.
Jiraiya easily dodged the attack. "So eager? Why don't we talk about what Orochimaru's been up to lately?"
The Sound Ninja didn't answer, but quickly formed hand seals. "Ninja Art: Sound Wave Explosion!"
High-frequency sound waves erupted in the confined space, shattering the experimental equipment. Jiraiya, prepared, clapped his hands. "Ninja Art: Toad Mouth Binding Technique!"
Suddenly, a fleshy membrane covered the laboratory walls, absorbing all the sound waves. Upon seeing this, the Sound Ninja immediately bit her finger. "Summoning Technique!"
A giant, multi-legged Centipede appeared in the smoke, crashed through the ceiling Jiraiya.
"Too inexperienced." Jiraiya shook his head, forming a hand seal with one hand. "Fire Style: Flame Bullet!"
The blazing fireball struck the Centipede's head precisely, causing the giant insect to writhe in agony and overturn several experimental cabinets. Taking advantage of the chaos, the Sound Ninja rushed towards the exit on the other side.
"Trying to run?" Jiraiya threw out several specially made Kunai, blocking all escape routes. "Confess honestly, where is Orochimaru?"
The Sound Ninja leaned against the wall, a resolute glint in her eyes. "I know nothing! I was just ordered to destroy the data!"
"On whose orders?"
"Lord Kabuto!" the Sound Ninja gasped, "He only told me to clean up this base, he didn't say anything else!"
Jiraiya stared into the other person's eyes, assessing their sincerity. After a moment, he sighed, "It seems you weren't lying." He approached the brazier and salvaged a few pages of documents that weren't completely burned. "What are these?"
Sound Ninja shook her head. "Experimental records... I was only responsible for destroying them, I didn't see the contents."
Jiraiya quickly scanned the torn pages, his brows gradually furrowing. The paper recorded the development process of a new type of Cursed Seal, with several runes hastily drawn beside it, somewhat similar to the Senjutsu seals he knew.
"Take me to see the experimental subjects," he suddenly commanded.
The Sound Ninja hesitated for a moment, then finally pointed to an iron door at the back of the laboratory. "There... there."
Behind the iron gate was a short corridor, at the end of which were several cell-like cubicles. Jiraiya pushed open the door to the first cell, and a pungent smell of preservatives hit him.
"This is..." His pupils contracted slightly.
On the operating table in the cubicle lay a twisted corpse, its skin an unnatural grayish-green, its limbs abnormally large, its fingertips claw-like, its head swollen and deformed, with several tumor-like protrusions even growing on its forehead.
"Natural Energy erosion..." Jiraiya muttered to himself. As a practitioner of Senjutsu, he was all too familiar with this symptom—it was the result of the body being devoured by the forces of nature after failing to absorb Natural Energy.
He quickly checked the other compartments, and the situation was similar. All the test subjects showed varying degrees of mutation, the most serious of which was no longer recognizable as human and looked more like a lump of flesh with limbs.
"Is Orochimaru... researching Senjutsu Mode?" Jiraiya's alarm bells rang.
Suddenly, an explosion rang out outside. Jiraiya whirled around. "A diversionary tactic?!"
He rushed out of the laboratory and found that the Sound Ninja had vanished, the brazier had been overturned, and embers were scattered all over the ground. To make matters worse, he heard hurried footsteps coming from the entrance—there was more than one person.
"Perverted teacher!" Naruto's voice rang out, followed by him and Karin appearing in the doorway, their faces filled with anxiety.
"Naruto? Didn't I tell you to stay at the inn?" Jiraiya frowned.
"We've discovered two more Sound Ninja have headed towards town!" Naruto said urgently. "Karin said their Chakra is the same as what we sensed before!"
Jiraiya's expression changed. "Damn it, their target might be the people in town!" He quickly made a decision. "Karin, lead the way! Naruto, prepare for battle, but remember—don't be reckless, these might be Orochimaru's new experimental subjects!"
The three quickly left the mine and sped towards the town. Night had fallen, but an unusual red light shone in the direction of Hot Spring Town—the glow of flames.
"Has it already begun...?" Jiraiya and sped up. "Naruto, listen up! If you encounter Cursed Seal ninja, don't engage in close combat! A body corrupted by Natural Energy is extremely dangerous!"
"Understood!" Naruto's eyes blazed with fighting spirit. "This time, we must capture them and find out Sasuke's whereabouts!"
Karin suddenly stopped in her tracks. "Wait... the Chakra reaction has disappeared!" Her face paled. "No... it didn't disappear, it's... changed?"
Jiraiya's heart tightened. "What do you mean?"
"It's like... the feeling of those test subjects..." Karin pointed tremblingly to a warehouse on the edge of town, "There!"
When they arrived, the warehouse was already half destroyed. Two figures stood in the middle of the ruins, one kneeling on the ground in agony, his body convulsing and swelling; the other coldly watched his companion's transformation, holding an empty syringe in his hand.
"It failed..." Sound Ninja Ren muttered to himself, holding the syringe. "Sample number fifty-seven is still unstable..."
He noticed Jiraiya and the others' arrival and gave a strange smile, "Ah, Sannin- sama, one of the Lord Jiraiya... Perfect, we need a strong person like you as a test subject..."
Before he could finish speaking, his companion let out a non-human howl, his body completely mutated, and lunged at the nearest target— Karin.
"Get out of my way!" Naruto formed hand seals and summoned a clone, "Rasengan!"
The rapidly spinning Chakra ball hurtled out, but Jiraiya and changed its direction before it could hit.
"Idiot! Didn't I tell you not to come near!" Jiraiya shouted, unleashing a string of Sealing Tags at the same time.
The mutated Sound Ninja crashed into the sealing wall, letting out a piercing roar. Another Sound Ninja seized the opportunity to form hand seals. "Summoning Technique: Centipede!"
Countless tiny Centipedes surged from the ground, forming a tidal wave of attack. Jiraiya swiftly formed hand seals. "Fire Style: Great Flame Bullet!"
Flames clashed with the Centipede swarm, filling the air with a burnt smell. In the chaos, a mutated Sound Ninja broke the seal and attacked Karin with a claw.
"Karin!" Naruto rushed forward, but was sent flying by a tremendous force. At the critical moment, a white hair shot out like a steel needle, pinning the mutated Sound Ninja to the ground.
"Wild Lion's Mane Technique!" Jiraiya's hair rapidly grew longer, forming a lion's head shape to entangle his opponent.
The battle ended quickly. The ordinary Sound Ninja were subdued by Jiraiya, while the mutated Sound Ninja died from their energy going out of control and exploding. However, they also failed to provide any useful information about Orochimaru or Sasuke.
It was late at night when Naruto returned to the hotel. He sat dejectedly in the hallway. "Another wasted effort..."
Jiraiya patted him on the shoulder. "Not necessarily. At least we know what Orochimaru is researching." His expression was serious. "A new type of Cursed Seal combined with Natural Energy... this is no joke."
"Um... Lord Jiraiya," Karin asked cautiously, "Those experimental subjects... were they...?"
"Hmm, it's very similar to the symptoms of failed Senjutsu training." Jiraiya nodded. "Orochimaru might be trying to forcibly control Natural Energy through the Cursed Seal... a crazy idea."
Naruto looked up. "Pervy Sage, what do we do next?"
Jiraiya gazed at the night sky outside the window. "Continue training, continue searching. Orochimaru's experiments won't stop; as long as he's active, he'll always leave new clues." He turned to Naruto with a smile, "But before that... how about we go for a soak in a hot spring tomorrow?"
Naruto made a face. "You just want to see the women's bath, don't you!"
The laughter of the three echoed through the hot spring inn, temporarily dispelling the gloom of the night. However, Jiraiya knew in his heart what Orochimaru's new research meant—a more dangerous Cursed Seal, a more powerful enemy, and... an even greater risk that Sasuke might face.
He secretly resolved that he must accelerate Naruto's Senjutsu training. Because the next encounter might not be just about being a test subject...
On the other hand...
In the dimly lit underground Training Ground, Sasuke knelt on one knee, his entire body covered in purplish-black Cursed Seal marks. His breathing was heavy, and sweat mixed with blood dripped from his chin.
"Heh... heh..." He chuckled softly as he propped himself up, his Three-Tomoe Sharingan glowing crimson in the darkness. "This is... the feeling of Senjutsu Chakra."
Orochimaru leaned against a stone pillar, his golden snake eyes gleaming with satisfaction. "As expected of the Uchiha bloodline, he adapted to the new Cursed Seal in just five days." He licked his lips, "Much stronger than the previous test subjects."
Sasuke clenched his fist, and lightning exploded in his palm—no longer an ordinary Chidori, but a "Sage Art: Lightning Release: Chidori Sharp Spear" wrapped in Natural Energy. Arcs of electricity moved like living things across the walls of the Training Ground, instantly vaporizing the specially made targets.
(Strength...)
(This is exactly what I need...)
But when he closed his eyes, the images in the Heavenly Screen reappeared— Uchiha Itachi's Susanoo, the Totsuka Blade, the Yata Mirror... and that unfathomable power of his eyes.
(Not enough...)
(Far from enough...)
"Today's training program." Kabuto adjusted his glasses and unrolled the scroll. "This morning, we'll develop the Chidori Derivative Technique in its Cursed Seal form; at noon, we'll conduct Poison Resistance Test; and in the afternoon..."
Sasuke interrupted immediately, "Plus practical combat training."
Kabuto glanced at Orochimaru, who nodded slightly.
"As you wish, I will select ten test subjects. Although they have all lost their minds, they are extremely powerful."
Sasuke's Sharingan suddenly contracted, then a sinister smile appeared on his face, "Just what I wanted."
At midnight, Sasuke dragged his battered body through the corridor and returned to his room. He stood in front of the mirror, looking at the Cursed Seal spreading across his neck.
He drew the Kusanagi Sword, Sharingan reflected on the blade suddenly changed— the Mitsudomoe spun wildly, but ultimately nothing changed...
As the first rays of sunlight pierced through the cracks in the rocks, Sasuke had already completed hundreds of practice sessions of Lightning Release Chakra transformation. His palms were mangled and bloody from overuse of Chidori, but were being continuously healed by the restorative power of the Cursed Seal.
"Are you in such a hurry to see your brother?" Orochimaru appeared behind him like a ghost.
Sasuke didn't turn his head. "The me in the Heavenly Screen isn't even half as strong as Itachi." His voice was icy cold. "How could someone of that level kill him?"
Orochimaru looked at Sasuke and suddenly said, "Do you know? The conditions for awakening the Mangekyō Sharingan..."
Sasuke suddenly turned around.
"... It's killing your closest loved ones with your own hands." Orochimaru's breath carried the smell of blood, "Just like what Itachi did back then."
The Training Ground fell into a deathly silence. After a moment, Sasuke's cold laugh broke the silence:
"Then I must thank you even more." His Chakra suddenly went berserk, "Allowing me to sever all ties early on."
Orochimaru paused, then let out a hoarse laugh, "Interesting! Let me see..." His body gradually transformed into White Snake and dissipated, "... How far can you go?"
As the sunlight fully illuminated the Training Ground, Sasuke began a new round of training. The images from the Heavenly Screen kept replaying in his mind: Danzo Sharingan his arm, Itachi's unfathomable Dōjutsu, the Five Kage's crushing defeat...
(Just wait...)
(Everyone who has harmed the Uchiha...)