The oil lamp had nearly burned dry. Its wick crackled twice, making the shadows on the wall twist and sway. Rinto stared at the plans spread across the stone table, the charcoal pencil between his fingers poised for almost half a minute without making a mark.
After working through the night, he had dismantled and rebuilt Carrier-Version Senjutsu's fixed anchors. Following the nodes along the chakra pathways, he had placed a nested locking anchor at each of four locations-the dantian, chest, shoulder and neck, and left arm-and linked them with Whirlpool Sealing patterns. He hoped layers of reinforcement would contain the impact of natural energy.
The logic on paper held together, but he had no confidence in it. Anchors were rigid structures, while chakra pathways were living things. Chakra flowed without pause, and natural energy was even less predictable. No matter how airtight the design looked on paper, there was no telling what might go wrong inside a body.
But without trying, he would never know where he had gone wrong.
He tossed the charcoal pencil onto the table and rubbed his stiff shoulders and neck. After an entire night awake, even moving his eyes made them feel dry and gritty. The draft chilled the sweat on his back, and his empty stomach cramped, but he had no desire even to reach for his rations. In his earlier fight with Orochimaru, Carrier-Version Senjutsu's clumsiness had already nearly killed him. If he did not refine Barehanded Senjutsu, the next tough opponent would leave him unable to save his own life, let alone conduct research.
Rinto walked to the emptiest corner of the laboratory, where he had already laid several high-pressure sealing talismans at his feet. He had brought them from Konoha specifically to suppress rampaging chakra. Taking out an engraving knife, he carved a miniature chakra-dispersal anchor into his right palm. The blade cut too deep, drawing beads of blood. He merely wiped them away, checked that the pattern was correct, and closed his eyes.
Chakra rose slowly from his dantian and spread along his pathways. Holding his breath, he pinned all his attention on his dantian, controlling his chakra to build nested whirlpool patterns layer by layer. The anchor gradually solidified and fastened onto a pathway node. His chest, shoulder and neck, and left arm followed. The four anchors settled into place one after another, linked by fine Chakra Threads to form a complete balancing system.
The first step caused no trouble. Rinto let out half a breath of relief but did not dare let his attention wander. He began drawing the surrounding natural energy into his body at an extremely slow pace.
For the first dozen seconds or so, it really was stable. Thin natural energy seeped through his pores, was caught by the anchors, and slowly merged with his physical and spiritual energies to produce a tiny amount of senjutsu chakra. There was very little, far less than with the carrier version, but at least it had not collapsed.
Rinto relaxed a little and tried increasing the intake of natural energy very slowly. He did not dare raise it sharply, increasing the amount by less than twenty percent.
But that tiny increase was enough to cause disaster.
The influx of natural energy was not linear at all. Once he loosened the threshold, it multiplied several times in an instant, pouring crazily into his pathways like water through a breached dam. The core anchor in his dantian immediately shook under the impact. He hurried to reinforce it with more chakra, but he could not keep up with the speed of the influx. The four rigidly fixed anchors lodged in his pathways failed to steady the flow. Instead, like immovable rocks sunk in a riverbed, they sent the surging energy crashing wildly in every direction.
"Fuck."
Rinto forced out a curse and tried to cut off the intake of natural energy immediately, but it was already too late. The balance between the three energies shattered outright. The newly formed anchors were smashed to pieces, leaving not even a trace. Uncontrolled natural energy rampaged through his pathways. Blue-gray petrification patterns first appeared on his fingertips, spreading with frightening speed along his fingers and palms and past his elbow in the blink of an eye.
His pathways felt packed with red-hot needles. The pain pulled every muscle in his body taut, and cold sweat instantly soaked the back of his clothes. Gritting his teeth, he activated the emergency anchor in his palm and dispersed all the chakra in his body with everything he had. But he could not retrieve the natural energy that had already entered his pathways. The petrification patterns kept climbing, passing his upper arm and threatening to reach his shoulder and neck.
If they really spread to his chest and dantian, he would be ruined.
Forcing his stiffening body to move, Rinto bent down and grabbed the sealing talismans at his feet, his hand trembling so badly he almost could not hold them. He slapped the first onto his left arm. The moment he poured chakra into it, the violent energy scorched the paper black and curled its edges. Gritting his teeth, he slapped them on one after another. Only after applying four in succession did he finally pin the uncontrolled natural energy firmly within his left arm. The petrification patterns stopped beneath his armpit and climbed no farther.
The instant the crisis was contained, his legs gave way. He slid down the stone wall and sat on the floor, gasping for breath. His left arm was so numb it felt as though it belonged to someone else. The energy had split his skin in several places, and blood mixed with sweat dripped down. Wave after wave of stabbing pain in his pathways made him bare his teeth.
It took nearly twenty minutes for the piercing pain to ease a little. Bracing himself against the stone wall, Rinto stood and limped back to the stone table. He stared at the fixed-anchor plans he had drawn the night before for less than half a minute, then swept the entire stack onto the floor.
Paper scattered everywhere. He did not pick it up. He merely clenched his back teeth and stared at the blank wall, reviewing what had happened.
It was wrong from the very foundation.
He had kept thinking about "locking down" natural energy and using anchors to "fix" the balance in place. But pathways were living, chakra flowed, and the rate at which natural energy entered changed constantly. Imposing a rigid structure on a living flow went against the underlying principles.
There were three core reasons it had collapsed so quickly. First, fixed anchors had a velocity relative to flowing chakra, so their locking response always lagged half a beat, and one surge of natural energy sent everything out of control. Second, the four anchors operated independently. When one failed, the whole system collapsed, with no redundancy at all. Third, the anchors could not accommodate energy differences between body parts. Natural energy entered the limbs and torso at different rates. A fixed locking strength either could not hold it or would block chakra circulation completely.
The more he thought about it, the more laughably stupid his earlier approach seemed. He had spent so many years working on dynamic reconfiguration. Adjusting structures to follow changes in chakra was what he did best. How had he ended up stuck in the dead end of "fixed" structures when it came to Senjutsu?
Frustrated or not, he still had to treat his wounds. He opened the medical kit and dug out iodine solution and gauze. His left arm was too numb to use properly, and his right palm was wounded too, making his movements terribly clumsy. He pulled over the incomplete Land of Whirlpools sealing scroll lying at the edge of the table and tucked it under his arm. He had pried this scroll out of the Martyrdom Sealing ruins. When repairing the island's defenses, he had consulted it every day. He was already thoroughly familiar with its Whirlpool Sealing structures, and notes he had casually drawn earlier still filled the margins.
His hand still shook as he poured the iodine, spilling quite a bit onto the scroll and blurring some of his earlier annotations. Rinto frowned, set down the bottle, and blotted it with clean gauze. He was not worried about ruining the scroll, but about blurring the structures he had marked for repairing the barrier.
As the gauze brushed over the page, his gaze fell on a line of small writing he had made earlier: "Inner layer of Martyrdom Sealing: adaptive locking structure. Anchors open and close automatically according to pressure, with no fixed nodes."
He had written that line half a month ago. While dismantling the Land of Whirlpools' Martyrdom Sealing, he had encountered a particularly troublesome nested seal. Instead of locking itself down through fixed formation cores, it had countless miniature anchors distributed across the entire formation. Where pressure was high, the anchors tightened automatically; where pressure was low, they released automatically. It had taken him three days of dismantling to grasp its logic. He had casually jotted down that line, then forgotten all about it, thinking only of using the structure in defensive barriers.
But now, that line was like a needle, piercing the knot that had blocked his thoughts for so long.
If fixed anchors didn't work, why not make anchors with "no fixed nodes"?
Just like that adaptive seal, he did not need to drive a few rigid stakes into his pathways. Instead, he could embed countless miniature balancing units along the entire route of chakra circulation. Wherever the chakra flowed, the anchors would follow. When natural energy increased, the units would automatically tighten their locking ratio; when it decreased, they would relax the pace of fusion. Rather than withstand the torrent head-on, he would divide it into countless small streams, each with its own little gate adjusting alongside it.
Rinto's breath caught, and he even forgot the pain in his arm. He abruptly lifted his arm off the scroll. Ignoring the blood still seeping from his wounds, he grabbed a fresh sheet of rough paper, picked up the charcoal pencil, and began to draw.
He did not spare the old fixed-anchor plans another glance. The new sketch had no core anchors rigidly fastened to pathway nodes. In their place were countless miniature closed-loop units distributed along the routes of chakra circulation. Each unit could independently handle energy fusion and balance while also linking with the surrounding units. If one spot developed a problem, neighboring units could immediately fill in, preventing a single failure from bringing everything down.
As he drew, he muttered deductions meant entirely for himself: "The earlier delay problem-if the anchors move with the chakra, relative velocity becomes zero, and the locking delay disappears..."
"Each unit only handles chakra within a tiny area. That improves balancing precision and prevents local imbalances..."
"Even if a few units collapse, they won't affect the whole body. The risk of backlash can be kept to a minimum..."
The last of the oil burned away. The flame wavered and went out completely. Outside the window, the sun had long since risen overhead. Noon sunlight streamed through the vent onto his densely covered sketches and his hands, stained with charcoal dust, blood, and iodine.
He noticed none of it, utterly absorbed in the new anchor structure. The numb ache in his left arm had never faded, but the ideas in his head had drawn away all his attention. It was as though the pain did not exist.
Only when his stomach gave a loud growl did he abruptly come back to himself. He looked outside and realized it was already noon. He had long since finished the rations he carried, and there was not even half a scrap of flatbread in the laboratory, but he had no inclination to go out and find food.
The new approach had taken shape, but plenty of pitfalls remained. How should he design the linkage logic between miniature units? How could he prevent them from interfering with one another? How could he control the total intake of natural energy to avoid a situation where local areas were stable but the whole system was overloaded?
He glanced down at his left arm. The petrification patterns had not faded, and the iodine stung his wounds. Picking up some gauze, he hastily wrapped it twice around his arm without even tying the knot securely, then turned and sat back on the stone stool. Charcoal pencil in hand, he worked through the sketch's details bit by bit.
The lingering fear of having nearly lost half his life, the pain of the backlash, and the exhaustion of staying awake all night were swept away by the new approach. To him, taking a fall was not frightening. What frightened him was falling and still not knowing where he had gone wrong. Now he had not only found the mistake but also discovered a new path. That little danger and pain were not worth mentioning.
He also knew perfectly well that this new distributed adaptive anchor demanded over a hundred times more precision in chakra control than fixed anchors. Countless miniature units had to operate simultaneously and link in sync. The slightest mistake could still cause problems.
But he had never been someone who feared risk.
If he had feared backlash and failure, he would never have fled Konoha in the first place, much less plunged into a field like Senjutsu that no one fully understood.
In Rinto's eyes, only the lines on the paper and the constantly unfolding chakra logic in his mind remained. The waves outside, the cries of seabirds, and his stomach's protests all became inaudible background noise.
Only chakra, only structure, only the still-unfathomed essence of Senjutsu mattered now.