The desert sun baked the rock walls until they burned, and the hot wind swept grit against the stone with a fine crackling sound.
Rinto crouched in a shaded hollow, his charcoal pencil scratching over rough-edged paper. There were no complete ninjutsu patterns on the page, only crooked diagrams of cellular structures covered in densely packed parameters. Arrows marking chakra circulation had been drawn and crossed out repeatedly, and his grip had frayed the paper's edges. A water flask lay tilted at his feet, half a mouthful gone, while his backpack had been tossed carelessly onto the sand, its zipper still open, exposing rolled-up documents and several carving knives.
He had been out of Falling Sand Town for almost a day, deliberately taking desolate paths that even traveling merchants avoided. He was not afraid of bounty hunters or hiding from Root pursuers. He simply found crowded places noisy-any disturbance could interrupt the Yang Release logic that had occupied his mind throughout the journey.
Jiraiya's booklet said that the core of Takigakure's secret bodily techniques was "nourishing cells with chakra, expanding energy through cells." Those few words laid bare the foundations of Yang Release. But how was he supposed to nourish them? How could he improve the conversion rate of bodily energy without damaging the limits of cellular division? He had been stuck for almost an entire night.
The charcoal pencil stopped between his fingers, and Rinto's gaze settled on a clump of camel grass in a crack in the rock. Despite months of drought in the desert, this grass was still alive. Its leaves had curled into slender needles, their waxy surfaces sealing in what little moisture remained. Even the stomata were tightly closed, keeping every trace of nutrients inside the cells without letting any escape.
His previous approach had been wrong.
He had kept thinking about engraving miniature anchors into every cell, locking bodily energy inside them the way he had made the Senjutsu Anchor before. But the human body contained tens of trillions of cells. Too many anchors would block the chakra pathways; too few would fail to maintain control. It was like forcibly spreading the camel grass's leaves-it would only kill it faster. Rather than locking them individually, he should create an adaptive regulatory mechanism. Like the grass's cell walls, it would let the cells decide when to retain or release energy, storing excess and releasing it when supplies ran low. He would not need to impose fixed rules on each one.
The thought shot through his mind like an electric current. Rinto immediately bent over and rapidly sketched the regulatory membrane structure he had just envisioned, even lightening his breathing.
He had barely drawn half the framework when a sudden boom rang out in the distance. The shock wave of colliding ninjutsu traveled along the rock walls, shaking loose stones overhead. One landed right on the edge of his paper, knocking one of his newly drawn lines askew.
Rinto's hand froze. His brows knotted instantly, and the concentration in his eyes gave way to vicious anger. His first reaction was to pin down the half-filled page before looking toward the noise, his face cold as ice.
Before he could get up, three blood-soaked rogue ninja rushed around the bend in a blind panic. Two Konoha Chunin followed, throwing ninjutsu as they pursued, the piercing whistle of kunai trailing explosive tags cutting through the air. The rogue ninja froze briefly when they spotted Rinto in the hollow. Assuming he was an ambush Konoha had placed ahead of them, they launched a Great Fireball without a second thought. Scorching heat and sparks hurtled straight toward him-they would force him back with fire first to avoid being caught between two sides.
Rinto remained seated, not even putting down his charcoal pencil. A faint wisp of chakra seeped from his fingertips. Half a meter in front of him, the incoming Great Fireball instantly dispersed, its sparks extinguished completely, as though that imposing Fire Release attack had never existed.
The three rogue ninja went pale and skidded to a halt. Having escaped Konoha ninja, they were hardened killers who lived on a knife's edge, but they had never seen anything like this. No hand seals, not even a raised hand, and he had casually erased a Great Fireball without a trace. What kind of monster was he?
While they stood stunned, Rinto flicked his fingers three times. Three nearly invisible chakra threads shot out and pierced their chakra pathways with precision. There was no explosion, no spray of blood. The three rogue ninja only felt their chakra suddenly descend into chaos, rampaging through their pathways like horses breaking their reins. They screamed in pain and collapsed together onto the sand, their ninja tools clattering to the ground. They could not even move their fingers.
The trouble was over in less than two seconds. Rinto barely raised his eyelids before returning his gaze to the paper. He wanted to continue drawing along his earlier train of thought, but no matter what he tried, the interrupted inspiration would not flow as smoothly as before.
"Don't move!"
The two Konoha Chunin caught up. Seeing the rogue ninja sprawled on the ground and Rinto crouching in the hollow, they instantly tensed, holding kunai across their chests as they watched him warily. They had never seen Rinto before and could only tell that his depths were unfathomable. What he had just done was more outrageous than anything their Jonin captain could manage.
Just then, more footsteps came from around the bend. Kakashi approached with a short blade in hand, the Sharingan beneath his mask still active. He had seen those few moves clearly-no hand seals, no burst of chakra. With just a few hair-thin strands of chakra, Rinto had directly rewritten his opponents' chakra circulation routes. Kakashi had only ever seen such absolute chakra control in one person: Second Hokage Tobirama Senju.
When he saw Rinto's face clearly, Kakashi's pupil contracted slightly.
He recognized this man. Uchiha Rinto, the subject of Danzo's S-rank wanted notice. Before defecting, he had been a core member of Konoha's Research and Development Department and possessed a bizarre technology capable of replicating kekkei genkai. Just a few days ago, the elite squad led by Kazama had fallen to him. Even Kazama himself had died.
Danzo's wanted notice described this man as utterly wicked and rated his danger at the highest level. Yet just now, he had merely disabled the rogue ninja without killing them. He had not even bothered getting up.
Seeing Kakashi arrive, the two Chunin immediately spoke. "Jonin Kakashi! These are the rogue ninja we were pursuing. This man..."
"I know." Kakashi raised a hand to interrupt them. His Sharingan slowly deactivated, and his gaze settled on Rinto, his tone carrying a measure of caution. "Uchiha Rinto?"
Rinto finally looked up, still gripping his charcoal pencil, his brows tightly furrowed. His first words were not an answer. "Take them away. Stop making noise here."
He had no attention to spare for Konoha ninja or wanted notices. His mind was full of the configuration that had just been interrupted, and he only wanted these people to disappear as quickly as possible and stop disturbing his thoughts.
Kakashi paused, then felt somewhat helpless. He had imagined many ways their meeting might go: a tense confrontation, or even an immediate fight. This was the one reaction he had not anticipated. The other man paid no attention to his standing as a Konoha Jonin and simply found them noisy.
"You're wanted by Konoha." Kakashi took half a step forward, his voice remaining level. "You should know about Danzo's wanted notice."
"If Danzo wants to catch me, let him come himself." Rinto folded the formula-covered paper twice, tucked it into his clothes, and swung his backpack onto his shoulder. "Don't bother me. I'm not interested in going back to Konoha with you."
He stepped around the rogue ninja on the ground and started down the canyon, giving their confrontation no weight at all. But after only two steps, a scream suddenly came from deeper in the canyon, followed by a Chunin's anxious shout. "Kenta!"
Rinto stopped, his brows drawing even tighter. Was this never going to end?
He glanced back. The young Genin who had been following Kakashi had gone to investigate the fork on the other side and accidentally triggered a trap the rogue ninja had prepared. He lay sprawled on the ground, the wound on his leg tinged blue-black. Poison crept upward through his blood vessels and had already reached his groin. The veins beneath his skin had turned dark green. His entire body convulsed in pain, and even his screams were growing weaker.
The two Chunin were about to rush over in panic when Kakashi stopped them. His Sharingan activated again. He could clearly see three linked traps between the fork and the fallen Genin, along with a triggered poison-mist seal. Charging in would only cost them more people, but disarming the traps would take time, and the boy's poisoning would not wait.
"This is a banned nerve poison from Sunagakure. If it isn't neutralized within six hours, all his organs will fail." One Chunin's voice shook with anxiety. "Jonin Kakashi, what do we do?"
Kakashi's expression darkened as well. He could disarm the traps, but even at his fastest, it would take over ten minutes. Kenta would not last that long.
While they stood at an impasse, Rinto suddenly moved.
He was not saving anyone out of kindness. The Genin's groans were too noisy, further disrupting his already broken inspiration. Rather than waste time listening to screams here, he might as well settle it quickly and make these people disappear.
He walked straight toward the fork. Kakashi paused but did not stop him. His Sharingan saw everything clearly: with each step Rinto took, another trap beneath his feet silently unraveled. The seal patterns on the ground instantly failed, and even the buried explosive tags became useless scraps of paper. He did not even look down, walking as though over level ground. Those traps that could bring down even Chunin were no different from roadside pebbles in his eyes.
Reaching Kenta, Rinto crouched without looking at his blue-tinged face. He formed a strand of chakra finer than hair at his fingertip and guided it into a blood vessel through the wound. He neither prepared an antidote nor used medical ninjutsu. He simply used the cellular isolation configuration he had only half worked out to form an extremely thin membrane along Kenta's blood vessel walls. First, he confined the poison that had not yet spread within the veins. Then, following the blood flow, he gradually separated the poison already mixed into the blood and forced it back toward the wound.
The whole process took less than a minute. He barely exerted himself, the chakra at his fingertip as steady as cast metal. When he withdrew his hand, he made a tiny incision in the wound with a carving knife. Blackish-purple poisoned blood flowed out, and Kenta's convulsions instantly stopped. Most of the ashen blue tint faded from his face as well.
"He won't die." Rinto stood and dusted off his hands. "An ordinary antidote can clear out the rest. Don't let him scream again."
Throughout the process, he had not spared Kenta a glance, much less paid attention to the two dumbstruck Chunin nearby. To him, what he had done was no more than casually correcting a faulty configuration and trying out an idea he had just conceived. It did not even count as an experiment.
But the shock Kakashi felt was far greater than when he had watched Rinto disable the rogue ninja.
His Sharingan had captured every movement clearly. That had not been medical ninjutsu, but absolute control over cells and chakra flow. He could even see that the isolation membrane Rinto formed followed the cellular structure of the blood vessel walls, fitting them with precision down to individual cells. It had contained the poison without damaging the slightest bit of vascular tissue. Forget ordinary medical Jonin-even Lady Tsunade herself might not have managed such precision with so little apparent effort.
What concerned him even more was that the logic of Rinto's configuration shared something with the core of the Second Hokage's sealing jutsu, yet was more flexible and reached into every gap. Danzo called this man a dangerous rogue ninja, but he had not shown the slightest killing intent from beginning to end. He had acted either to defend himself or because he found something troublesome. Throughout it all, his eyes had held nothing but that formula-covered sheet tucked inside his clothes.
"Thank you." Kakashi gave Rinto a slight nod. Most of the caution had left his voice, replaced by sincere gratitude.
"No need." Rinto walked around him and continued toward the canyon's exit. "Take them away already. Stop holding me up."
"Wait." Kakashi called him back again.
Rinto stopped without turning around, merely angling his face slightly. Impatience all but spilled from his voice. "Anything else?"
"Will you really not consider returning to Konoha?" Kakashi took two steps forward. "About Danzo's wanted notice, I can help explain the situation to Lord Third Hokage. You were a Konoha ninja to begin with. As long as what happened back then is explained, it might still be possible..."
"No need." Rinto interrupted him and finally looked back. His gaze was calm, but his certainty allowed no question. "Would Konoha's laboratories let me research in peace? Would Danzo stop coveting my technology?"
Those questions left Kakashi speechless.
He knew Danzo's methods all too well. If Rinto returned to Konoha, Danzo would absolutely use every means available to extract the technology in his head. Forget researching in peace—it was doubtful he could even keep his freedom. Danzo had been the reason Rinto defected in the first place.
Rinto wasted no more words on him. He turned and walked away without the slightest hesitation, soon reaching the bend in the canyon and disappearing behind the rock wall.
"Jonin Kakashi, are we just letting him leave?" one Chunin could not help asking. "He's an S-rank wanted criminal. If Lord Danzo finds out..."
"Say we never encountered him." Kakashi withdrew his gaze and sighed. "Treat Kenta's injuries first, then escort the rogue ninja back. I'll handle Danzo."
He knew perfectly well that not only were they incapable of stopping Rinto, but even if they could, they should not. Danzo's wanted notice had served his own agenda from the start. Rinto was no rogue ninja threatening the shinobi world. Insisting on capturing him would only push this unfathomable man completely onto Konoha's opposing side.
Meanwhile, Rinto had already left the canyon and continued northwest along the desert trail.
The cellular isolation configuration he had casually tested while removing the poison had completely cleared his earlier mental block. He took out a notebook and charcoal pencil as he walked, drawing on the move, his pace alternating between fast and slow. His mind was full of ways to optimize the adaptive regulatory membrane's parameters. He did not even notice when the wind blew his hood off.
Previously, he had kept thinking about embedding Yang Release logic into chakra pathways and cells. But that brief test had shown him that the core of Yang Release had never been "locking," but "adaptation." Just as that clump of camel grass could adapt to the desert's drought, what he needed was to make chakra circulation adapt to the body's cells, rather than forcibly impose fixed rules on them.
As for the Konoha ninja, Danzo's wanted notice, or even whether anyone was following him, he took none of it to heart.
If trouble came, he would simply deal with it. As long as it did not interrupt his thoughts or delay his research, even the sky falling would matter less than the half-page configuration in his hand.
Behind a dune several kilometers away, two Root scouts stared fixedly at Rinto's receding figure. Their messenger hawk was ready, and they were urgently sending word of his movement toward the Land of Waterfalls back to their base in Falling Sand Town.
Rinto remained entirely unaware—or rather, even if he noticed, he would not care. All his attention rested on the entirely new basic Yang Release framework he had just drawn in his notebook.
The Land of Waterfalls was still a long way off, but his Yang Release research had already torn open a gap.