Arai took the two boys to another sector near the border of the Land of Rain, far enough from the area they had raided before that the enemy would not immediately connect the two incidents. After contacting the Sand shinobi stationed there and gathering a rough picture of the local situation, the three of them rested for a day. Then, once night fell, Arai led them across the border again.
Everything unfolded much like last time. Arai concealed himself in the shadows to observe their performance and intervene only if their lives were truly in danger. As for Yubi and Sasori, the two of them split off and acted alone the moment they entered enemy territory.
Having already gone through this kind of mission once, both boys were noticeably calmer than before. The unfamiliar pressure had not vanished, but it no longer had the power to freeze them. They had already tasted what it meant to move through the Land of Rain with death hiding behind every tree.
Before they separated, Sasori crossed his arms and stared at Yubi with his usual cold expression. "If you lose again this time, you won't have anything to say."
He had clearly learned from the last mission. His tone still carried that same domineering edge, but he no longer meant to expose himself recklessly just to overwhelm the score. This time, he wanted to beat Yubi properly.
Yubi only scratched his head and smiled. "There's no way I can compete with you. You're a genius puppeteer. I'm just a medical ninja."
Compared to Sasori's sharp, confrontational attitude, he looked almost careless. It was as if he did not care about the competition at all.
Those words only made Sasori frown. His face darkened in obvious displeasure, but he said nothing more. He simply turned and vanished into the forest first.
Yubi also slipped into the darkness.
A short while later, from a crack in the shadows between the branches, a pair of calm eyes locked onto two Rain shinobi on patrol. The two of them were moving at an unhurried pace, chatting as they leaped from tree to tree. Their posture was loose, and their guard was nothing compared to the tension of the central front. They had no idea that someone was already watching them from the dark.
Yubi tugged lightly on the wire wrapped around his fingers.
A silver flash cut through the night.
The first Rain shinobi had only just landed on a tree trunk when his head flew clean off his shoulders. The cut was so fast and so sharp that for an instant even the blood seemed delayed. Then it erupted in a violent spray.
The second Rain shinobi froze in shock. "What was that?!"
He had seen only a streak of light. There was no visible enemy, no footsteps, no voice, no warning. Just the impossible image of his companion dying beside him for no reason he could understand.
Whoosh!
Another faint sound reached his ears. This time, prepared and staring hard into the darkness, he finally managed to catch sight of the thing that was killing them.
It was a scalpel.
The blade was tiny, light, and nearly silent even at high speed. Because it made so little noise and reflected so little light, it was absurdly difficult to notice in motion. By the time the Rain shinobi truly saw it, it was already too late to dodge.
If he had known where it was from the start, he might have been able to evade it. But this style of attack was too insidious. It gave the enemy nothing to predict, nothing to defend against, and almost no time to react.
His head was severed just like his companion's.
The flying scalpel arced once through the air, then snapped back into the darkness as if pulled by an invisible hand. At the same time, Yubi used his wire to hook both corpses and drag them into the undergrowth. The entire sequence took only a blink. Quiet, clean, and terrifyingly efficient.
Yubi watched the bodies disappear into the weeds and nodded to himself. "Not bad."
He was genuinely pleased with the result, but he still noticed the flaws at once. "Since I'm not guiding the force directly with my hand, the angle and cutting strength still aren't precise enough. Too much blood splatter. That's troublesome."
Even so, the new technique had performed better than expected.
He lowered his gaze to the thin wire in his hand and thought for a moment. If Arai was really watching from somewhere nearby, he would need an explanation for this method. He could not very well say that he had exchanged a skill through a system. He needed something believable - something that fit the identity he had already built for himself inside Sunagakure.
"Let's call it Blade Thread Manipulation," he murmured. "The inspiration came from puppet techniques... from chakra threads... and I adapted it into my own ninjutsu."
In truth, methods involving wires and hidden blades were not unheard of in the shinobi world. Similar ideas had appeared before, often mixed with ninja tools or hidden weapon techniques. Sasuke had even used thread-based tactics in battle, combining them with other attacks. But Yubi's version was different.
First, the wire itself was specially prepared and extremely hard to detect with the naked eye. Second, the skill had been assimilated by the system and turned into a ninjutsu uniquely suited to him. Once active, it allowed him to guide the scalpel through the air with a lethal flexibility ordinary shinobi could not easily reproduce.
To anyone watching, the blade did not merely fly. It danced.
And Arai was watching.
He was hidden not far away, closer to Yubi than to Sasori. Compared with Sasori, who had already proven his strength time and again, Arai was still more worried about Yubi. So when the first kill happened, he had paid very close attention.
Even then, he almost had not seen it clearly.
"Was that... his scalpel?" Arai narrowed his eyes, stunned. "What kind of technique was that?"
The shock he felt was not small. During the previous mission, Yubi had relied on close-range combat, traps, and precise assassinations. He had never once shown anything like this. Arai had assumed he already understood the boy's limits. Clearly, he had been wrong.
Soon, the disappearance of the two patrol members drew another small group over to investigate. This time Arai moved closer and watched more carefully from the shadows.
Now he saw it.
The scalpel was tied to a nearly invisible thread and manipulated from afar, not unlike a puppeteer controlling a puppet. What startled Arai was not just the method, but the finesse. Yubi could control the blade at considerable range with impressive power, speed, and subtlety. More frightening still was the secrecy of it. With such a fine thread and such a tiny weapon, the enemy could be killed before they even realized an attack had begun.
"It has elements of ninja tool manipulation, some traits of hidden weapon techniques... and yet it also resembles a puppeteer's chakra threads," Arai thought, his expression turning stranger by the second. "I've never seen this ninjutsu before."
If it were him, he believed he could defend against it under normal conditions. But battle was not fought under normal conditions. A person's mental state shifted. Their attention wandered. Their posture changed. Their assumptions betrayed them. In the right moment, the unpredictability and assassination value of this technique were high enough that even a jonin could die to it.
Arai sucked in a quiet breath of cold air.
Yubi had been hiding a move like this all along?
He had not used it even during the earlier mission in the Land of Rain, when the danger had been far greater. Just how many things was this little brat still concealing?
For the first time, Arai felt that he could not quite see through Yubi at all. The boy had clearly claimed he had no interest in becoming a puppeteer. Looking at him now, though, it almost seemed as if he had secretly made a great many preparations in exactly that direction.
"Two-faced little rascal," Arai muttered inwardly, equal parts speechless and amused.
Meanwhile, on the other side of the forest, Sasori had already started his own hunt.
This time he did not repeat the same mistake as before. He was still Sasori, still ruthless, still frighteningly gifted, but his methods had become noticeably quieter. Rather than causing a large disturbance, he used his puppets with cold precision, eliminating patrols without exposing himself and erasing the traces at the scene as he moved on.
It was clear that Arai's evaluation from the previous mission had gotten under his skin. Sasori might not admit it aloud, but he had listened.
In terms of assassination alone, the puppeteer's methods were terrifying when used properly. His puppets moved in silence, struck from angles ordinary shinobi could not predict, and possessed mechanisms that made a single mistake fatal. Under Sasori's control, those tools became extensions of his will, slipping through the forest like patient predators.
Time passed little by little. One Rain patrol vanished, then another, then another. The emptier the surrounding routes became, the more unnatural the situation grew. Before long, the repeated disappearances began to alarm the entire local defense network of Amegakure.
Rain shinobi started appearing in larger groups throughout the forest. Search activity increased sharply, and the pressure in the air changed at once. The easy stage of the hunt was over.
But unlike the previous mission, Arai and the two boys were not thrown into disarray this time.
They had stayed hidden. They had controlled their pace. They had killed quietly and retreated before the enemy could form a proper net around them.
When the time limit of an hour expired, the three of them slipped away just as silently as they had entered. Even though Amegakure had already begun a broad search operation, none of them were caught in it. Their retreat was smooth, disciplined, and almost eerily clean.
For Yubi, it was the perfect first real test of his newly acquired blade-control technique. For Sasori, it was proof that he could adjust when he chose to. And for Arai, it was a confirmation of something increasingly difficult to ignore.
The two children under his watch were growing at a speed that no ordinary standard could measure.