Naruto: The Medical Ninja

Chapter 260: Chapter 257: Jisatsu Seal

Ryu gestured, and the screen displaying the [Unnamed Seal] drawing everyone’s attention. It didn’t take long for Dan and Tsunade to guess what it was.

”This is the seal,” Ryu began, his voice calm yet weighted with discovery. ”I found it etched onto the bodies of the ninjas who tried to kill me.”

Even if one cannot prove it, everyone knows what kind of squad Jisatsu Squad is in the upper echelon of the ninja world. A group of rogue ninjas tasked to obey orders under the threat of the very seal Ryu just displayed.

Tsunade’s eyes narrowed, a flash of grim recognition. ”The Jisatsu Seal,” she said. This squad and this seal had been active after the death of the Second Hokage and had been the backbone of Cloud Village’s version of ANBU Root.

As Tsunade spoke the real name of the seal, a fascinating transformation occurred on the floating screen. One letter at a time, the title began to shift, the characters randomising and rearranging themselves and then stopping at the right character.

[U] became [J], [n] became [i], and so on, until the words ”Jisatsu Seal” were spelt out in front of them. The implications of its presence here were troubling, to say the least. A collective, soft gasp escaped Shizune and Tsunade, a dawning surprise in their eyes.

Ryu nodded slowly, acknowledging the name. ”Jisatsu Seal,” he repeated, letting the name settle like a cold weight in the air. ”I deconstructed it in my mind, piece by piece. I found that this seal is a death trap. At its most basic, it’s a controlled explosive seal designed to force a ninja under threat of life into absolute obedience to its controller.”

Ryu paused, his gaze sweeping over their faces, allowing the chilling implication to sink in. ”But inside its core, I found something far more useful than a simple explosive.”

Dan interjected, his eyes gleaming with a sudden, profound understanding, a lifetime of Fuinjutsu knowledge recognising a masterwork of dark genius. ”A unique trigger mechanism,” he stated, almost reverently.

Ryu smiled and said, ”Precisely, Grandpa. And not just one. It has multiple, layered trigger mechanisms, like a nested set of traps, each more subtle than the last.”

Dan looked at the seal and replied, ”Our village has been trying to get its hands on this seal for decades, Danzo especially. It’s rumoured to be quite an effective control mechanism. Danzo and the creator of this seal, a man named Onnen, have very much in common—a shared philosophy of absolute control, no matter the cost. The cloud village had three grandmasters. Onnen is one of them. Each grandmaster has at least one original seal to their name. This is Onnen’s masterpiece.”

”Masterpiece Indeed, but its real value is lost to this Onnen idiot,” Ryu confirmed, his voice now laced with a cold, clinical detachment as he elaborated on the seal’s horrifying ingenuity. ”The seal has an internal counter, linked to biological sensors. In this case, it detects the ninja’s heartbeat. It uses the heartbeat as a time reference. Essentially, a person with this seal on is a living time bomb. If the criminal runs away with this, he dies eventually, his body utterly destroyed to prevent information leakage. Or, if the leader decides you are expendable, you die too. Kaminari, for instance, used his limited control over the trigger to try to kill me.”

Shizune said, ”So, if they’re captured, or even if they die naturally, their bodies are destroyed? That’s very convenient if you want deniability and a cover-up.”

”And efficient, from their perspective,” Ryu added, his tone devoid of judgement, merely stating a fact.

Ryu continued and said, ”But using it this way, as a mere self-destruct mechanism, is a colossal waste of the concept Onnen developed; it had so much more potential.”

”Grandpa once told me about the Root’s [Cursed Tongue Seal], and I’ve deduced that the cursed seals Danzo uses are similar, but they only work on spoken words with ill intentions against Danzo or his Root. They’re still a few levels below Onnen’s design, crude by comparison.”

Dan then elaborated, his gaze fixed on the glowing seal diagrams, a historian of forbidden arts. ”The difference, you see, is in the mechanism of control and the ultimate consequence. Onnen’s Jisatsu Seal is a constant, internal threat, a ticking clock linked to the very life force of the wearer. It compels absolute obedience, backed by the immediate and inevitable threat of self-destruction.”

”Danzo’s Cursed Seal of Tongue, while effective, is a more limited form of control. It’s a ’gag order’ seal that activates only when the wearer attempts to speak about his secrets or Root’s operations, causing intense pain and paralysis. While Danzo can modify it, his luck wasn’t so great even after trying it for decades.”

”You see, cooking such a seal requires... Let’s just say breaking some egg...if you know what I mean.”

Ryu replied, ”I know what you mean.”

Dan continued. ”He’s trying to outdo Onnen, but unlike someone I know,” Dan said, with a proud glance at Ryu, ”Fuinjutsu isn’t so easily mastered.”

Yuki, her mind already racing through the implications, began to list possibilities, her fingers tapping against her chin. ”If it can detect heartbeats... then it could detect irregular heartbeat syndrome. Or be adapted for lie detection, perhaps? The applications for intelligence gathering alone, for interrogation, for battlefield assessment...”

Tsunade replied, ”You are right sensei, but a ninja and a medical ninja think differently. He only had one thought in mind when he developed this seal ... two actually ... death and destruction.”

Ryu smiled and made a casual gesture. A new shimmering orb flew towards him, spinning gently before expanding into a second screen. It displayed a complex array of fuinjutsu texts laid in geometric formations and its title glowing: [Lie Detector Seal].

”Been there, done that,” Ryu stated casually, a hint of boredom in his voice, as if discussing yesterday’s breakfast.

Everyone in the Mind Palace was stunned into silence. Yuki’s jaw dropped, a rare sight. ”When did you...?” she finally managed, her voice a disbelieving whisper, her eyes darting between Ryu and the new screen.

Dan merely blinked, his own composure momentarily cracked, a faint, impressed whistle escaping him.

”I was bored when I woke up,” Ryu replied with a shrug, as if creating revolutionary Fuinjutsu was a common morning pastime.

Ryu then said, ”My point is, I know how to access a biological signal. So, I can also access neurological signals if I try. The principles are similar, just more complex.”

Tsunade, her mind reeling from the implications of a functional lie detector seal, quickly interjected, stepping in to bridge the gap between Ryu’s casual genius and their stunned comprehension. ”He plans to replace that part of the brain that governs motor function with a Fuinjutsu seal.”

She delivered the statement with the solemnity of a death knell, yet her eyes held a spark of the impossible. A collective, palpable shock vibrated through the Mind Palace. This was not what they had imagined. Not the kind of medical treatment anyone would hope for.

Fuinjutsu had never been used to aid in medical recovery, not before Ryu came along and developed the [Healing Seal]. It was a leap of faith, a defiance of every established medical and Fuinjutsu principle. The very idea felt like blasphemy to some, a dangerous dance on the edge of disaster. But for Ryu, it was a chance to rewrite the rules and save lives in a way no one had ever thought possible.

But like every groundbreaking discovery in medicine, it first had to walk in fire and be judged by the harsh eyes of the sceptical before it could be accepted as a legitimate form of healing.

Dan, however, did not doubt him. His gaze remained steady, a deep trust in his grandson’s abilities, a quiet pride in the lineage of ingenuity. Yuki, while visibly shaken by the sheer audacity of the plan, was somewhat trusting of Ryu and his intelligence. This was not the first time he had shown his brilliance, after all. But Shizune was not convinced. Her medical training screamed against such a radical, untried procedure.

”It will not be simple,” Shizune stated, her voice tight with apprehension, her gaze fixed on the disassembled brain, as if it might explode at any moment. ”The brain is too delicate, too intricate. One wrong stroke of chakra, one misplaced segment of a seal, and you could erase him entirely. You could turn him into a vegetable or, worse, a puppet!”

Ryu met her gaze, his expression softening slightly. ”It was not luck that I found this seal, Shizune-san. ”It was destiny,” he said, his voice quiet yet firm, radiating an unwavering conviction. ”It will not be easy, for sure, but I will do it nonetheless.”

”By my estimate, it will take a month of meticulous work, a constant dance on the edge of the impossible, demanding every single stroke of the Fuinjutsu block to be perfect. And this new seal we create, this [Jisatsu Seal] modified for healing, will become the Hamura Clan’s secret weapon in the future.”

A/N:

I am sick, so I apologise for the delays. I might take some breaks too.

Thank you, Alexis Chalifour and Chamar Ellis for supporting me on Patreon.