Ryujin Kenichi carefully observed the test subject lying on the operating table, their chest rising and falling with labored breaths. "This ninja's physical fitness is quite impressive, and they appear to have some resistance to Yang-attribute chakra," he muttered, eyes gleaming with curiosity.
To get a clearer look, he removed a section of the ribcage with practiced precision, completely indifferent to the fact that this would doom the subject. He had already successfully induced cancer in their lungs using controlled applications of Yang chakra, and the first signs of cellular abnormalities were beginning to emerge.
"Cough… cough…" The subject's breathing grew harsher, punctuated by fits of coughing. Kenichi silently increased the chakra infusion, carefully channeling Yang-natured energy directly into the rapidly multiplying malignant cells.
Cancer cells, after all, were simply rogue cells thriving on unchecked growth. But what if they were given an even greater abundance of life energy? The results were immediate—metastasis accelerated before his eyes, and the subject began spitting blood, struggling to inhale.
"My hypothesis is correct," Kenichi mused, excitement flickering across his face. "Yang-attribute chakra can stimulate the proliferation of cancer cells, making it possible to artificially induce cancer in a target."
Now, he only needed to refine the process, test the effectiveness across different subjects, and measure its success rate. If all went well, he would have created a unique and devastating jutsu—one that could bypass conventional defenses and silently bring even the most resilient shinobi to their knees.
"Hmm… the Mystical Palm Technique or even the Fine Extraction Technique might be capable of removing cancerous tissue, but those methods likely wouldn't work once the cancer has spread systemically," Kenichi mused, stroking his chin.
As he precisely injected another controlled dose of Yang chakra, he noted the rapid deterioration of his test subject. If this had been his previous life, such a case would be terminal—merely a countdown to the inevitable.
Having gathered sufficient data, Kenichi sutured the subject's wounds and handed them over to the base's medical team. He was eager to see whether the medical ninjutsu of this world could combat cancer. If they could cure it, his technique would need further refinement. If not, then he would have developed a truly insidious forbidden jutsu.
"Your experiment is over?" a familiar voice called as Kenichi entered another part of the lab. He turned to see Orochimaru standing near an operating table, where the lifeless bodies of two shinobi lay. A thick, musty scent filled the air, and a fine layer of dust coated the table's surface.
The scent… the dust… Kenichi's mind immediately connected the dots. Impure World Reincarnation?
"Yes, Orochimaru-sensei. The experiment yielded promising results. I've turned the subject over to the medical team to observe whether they can reverse the process." He maintained a respectful tone, careful not to betray any unnecessary curiosity.
Orochimaru nodded, his piercing golden eyes reflecting his ever-present intrigue. "Good. But do not neglect your ninjutsu training. A shinobi's worth is measured by their power in battle."
"Understood, sensei," Kenichi replied smoothly.
He had already structured his training plan—first, to strengthen his ninjutsu and taijutsu; second, to continue fulfilling assignments for Orochimaru; and finally, to perfect his cancer-inducing jutsu. He was on the path to developing a technique that could change the battlefield forever.
After obtaining Hashirama Senju's cells, Ryujin Kenichi gained an immense amount of Yang-attribute chakra. However, to his disappointment, he had not yet awakened Wood Release.
This left him somewhat frustrated. After all, Wood Release was one of the most powerful kekkei genkai in the ninja world, capable of restraining Tailed Beasts and shaping entire landscapes. If he could master it, capturing and studying the Bijū would become much easier.
Thinking about the sheer power of the Tailed Beasts, Kenichi couldn't help but feel a bit greedy. Though they had been overshadowed in later years by other threats, the villages still treated them like weapons of mass destruction, each one possessing unique and terrifying abilities.
"I have a jutsu that I intend to teach you," Orochimaru said, his voice as smooth and enigmatic as ever. Seated comfortably in his chair, his golden, snake-like eyes locked onto Kenichi with an unreadable expression.
Kenichi felt his heartbeat pause for a moment. A scene like this made it impossible not to overthink. Could it be that jutsu? The one capable of bringing the dead back to life? Impure World Reincarnation was one of the most forbidden techniques in the ninja world. He knew that using it required a DNA sample from the deceased, but in a world where cremation was uncommon, obtaining such samples wasn't difficult—especially not in a place like Orochimaru's hideout, which was filled with experimental remains.
Kenichi also knew the location of the Second Hokage's grave. If he could get his hands on Tobirama Senju's cells...
"Sensei, is it a Lightning Release technique from Kumogakure?" Kenichi asked, feigning excitement. He had to act within reason—after all, someone of his level wasn't supposed to have access to Konoha's most forbidden techniques.
Orochimaru merely chuckled and tossed a scroll toward him.
"No, it's something far more powerful. But also… more dangerous."
Kenichi caught the scroll and unrolled it. His eyes landed on the bolded kanji at the top: Impure World Reincarnation.
Even though he had expected it, seeing it in writing still made his heart race. This was a jutsu that could shake the foundations of the ninja world.
"What do you think?" Orochimaru asked casually, sipping his tea. His gaze, however, was anything but casual—he was studying Kenichi's every reaction.
Kenichi took a deep breath before responding. "It's an incredibly powerful jutsu… but also a dangerous one. Its practicality is undeniable, but once used, it's bound to attract a great deal of hostility."
Orochimaru remained silent, waiting for him to elaborate.
Kenichi sighed. "Because it manipulates the dead. No matter how effective it is in battle, it defies natural order. Many will see it as a desecration of the deceased."
Orochimaru smirked. "And yet, the dead care little for such concerns."
Kenichi shrugged. "True. But the living do."
Still, the potential of the technique was undeniable. If someone had cast Impure World Reincarnation during the Nine-Tails' attack on Konoha, summoning both Hashirama and Tobirama Senju, the outcome would have been completely different.
"Then I'll teach you." Orochimaru's smirk widened. "Do you dare to learn?"
Kenichi didn't hesitate. "Of course I do."
A forbidden technique like this? It would be foolish not to learn it.