"Oh? You wish to research the Impure World Reincarnation?" Orochimaru took a slow sip of tea, his serpentine eyes narrowing with amusement as he regarded his disciple.
"Yes, sensei. I believe the Impure World Reincarnation has immense practical applications," Ryujin Kenichi responded earnestly. His true intention, however, was to extract something more suitable for himself from the First Hokage's remains.
Despite having acquired Hashirama Senju's robust physique—his so-called Sage Body—Kenichi had failed to awaken the coveted Wood Release. It was an infuriating mystery. Given the First Hokage's natural affinity for Sage Jutsu, Kenichi theorized that mastering senjutsu could serve as an alternative path to greater power.
Orochimaru set his cup down, shaking his head. "I don't recommend you experiment with the Impure World Reincarnation just yet. The technique is still incomplete. If you insist on trying it, start with weaker test subjects. Reincarnating the First Hokage at this stage would be… problematic."
Kenichi immediately understood the unspoken warning. Hashirama's sheer power was legendary—even a flawed reincarnation might be impossible to control. And if word got out that Orochimaru was tampering with such a dangerous jutsu, the consequences would be catastrophic.
Seeing Kenichi's thoughtful silence, Orochimaru changed the topic. "Speaking of research, how is that pet project of yours progressing?" His golden eyes gleamed with curiosity. He had skimmed through Kenichi's experimental records before—though interesting, he had found the concept inherently flawed.
"It's going well, sensei. A few more trials should lead to a breakthrough." A rare smile crept onto Kenichi's face.
Most of his time was spent assisting Orochimaru with the study of Hashirama's cells and the Uchiha's Sharingan—projects funded generously by Danzo's Root, which supplied both financial resources and… experimental materials. However, Kenichi's personal research was more unconventional.
His goal was to refine a self-created jutsu—one designed to induce cancer.
Currently, he had achieved a crude success: by exposing a target's skin to nicotine, he could trigger the rapid development of lung cancer. Against a mere genin, the results were promising—within days, the target's respiratory function deteriorated significantly. However, the technique still had major drawbacks. It required prolonged exposure, took too long to incapacitate an opponent, and was ineffective against those with advanced chakra control.
"I see that your method weakens a target over time, but does it work on chunin or jonin?" Orochimaru inquired, his interest more pragmatic than ethical.
Kenichi sighed. "I haven't tested it on a higher-level subject yet. Acquiring such materials is… difficult." Unlike Orochimaru, he lacked direct authority within Root. War provided ample opportunities for human experimentation, but in peacetime, such chances were rare.
"The human body follows predictable principles," Orochimaru mused. "If it works on genin, it should work on stronger shinobi as well. The trick is refining it." His expression darkened with intrigue. "Cancer cells possess extraordinary regenerative properties. If properly manipulated, they could hold the key to immortality."
Kenichi's eyes flickered. Immortality...
Perhaps this research held greater potential than he had originally imagined.
However, Orochimaru hadn't placed all his hopes for immortality solely on the study of cancer cells. His research into the Impure World Reincarnation (Edo Tensei) was also ongoing.
It was just that the technique seemed to inflict damage to the soul. While it was possible that a reincarnated soul could recover over time, Orochimaru wasn't certain—he hadn't yet conducted enough experiments to verify it.
If cancer cells functioned similarly to Hashirama's cells, perhaps he would have considered using them to construct a new body for himself. However, unlike Hashirama's cells, which enhanced regeneration and vitality, cancer cells spread chaotically, ultimately leading to self-destruction. That instability made them unreliable as a method for immortality.
"Sensei, relying purely on theoretical data and reasoning in the pursuit of science is not enough!" Ryujin Kenichi said, his tone filled with conviction.
Orochimaru glanced at him before waving his hand dismissively.
"I can provide you with a chūnin-level test subject, but don't waste it," he said impatiently. This disciple of his was growing increasingly bold—he even dared to make direct requests of him.
"Thank you, sensei!" Ryujin Kenichi's excitement was evident. A chūnin-level subject! It wasn't that he couldn't defeat a chūnin himself, but acquiring one was troublesome.
He couldn't exactly go out and kidnap a shinobi from the village, could he? Well… he had considered it. After all, he was eager to observe the difference between a chūnin and a genin when subjected to his experiments.
However, the risk of exposure was too great. So for now, he would remain patient. The Nine-Tails' attack on the village would be an excellent opportunity to acquire more subjects.
"...Sensei, do you wish to observe the experiment?" Ryujin Kenichi asked curiously, glancing at Orochimaru.
Normally, his teacher barely paid attention to his independent research. What had changed today?
"Yes. I have nothing else to do," Orochimaru replied calmly. He rarely spoke unless it concerned research, and even then, his interest was selective.
Ryujin Kenichi had no objections. He simply followed his master to retrieve the test subject before leading him to his personal laboratory.
"Sensei, please disinfect first," he said politely.
While cancer cells wreaked havoc inside the body, they were still weaker than external pathogens. Maintaining a sterile environment was crucial. Ryujin Kenichi had gone to great lengths to modify his laboratory, ensuring strict contamination control.
Orochimaru complied without complaint, then stepped inside.
Once the subject was restrained, Ryujin Kenichi skillfully began his research.
First, he exposed the lungs to nicotine, simulating prolonged tobacco exposure. Then, with careful precision, he injected refined Yang-attribute chakra directly into the lung tissue.
Before his eyes, cancerous cells began to form.
Ryujin Kenichi was satisfied. He had spent a long time refining his control over Yang chakra's influence on cellular behavior, and this was proof that his efforts were yielding results.