Previously, Amemiya Kenichi's method of flooding subjects with Yang Chakra to induce respiratory alkalosis was too obvious, unreliable, and easily detectable.
Now, after refining his technique, he could diffuse Yang Chakra into the surrounding air. As others breathed it in, their lung cancer would steadily worsen.
Theoretically, Amemiya Kenichi believed this ninjutsu had the potential to evolve into a wide-area killing technique.
But for now, that wasn't necessary. He simply wanted to investigate how lung cancer affected Chūnin.
"Teacher, look here! The test subject's lungs are already showing early signs of lung cancer," Amemiya Kenichi said excitedly to Orochimaru. Just as he'd predicted—even Chūnin were still human.
As long as you're human, as long as you need lungs to breathe, you can't escape the effects of lung cancer.
Perhaps early-stage cancer wouldn't significantly impact combat ability, but what about later stages?
What about the terminal phase?
Amemiya Kenichi had visited the oncology ward of a hospital to see his relatives. The patients in the late and terminal stages of cancer were truly pitiful. Their bodies could barely support movement; even lying down was agony, as intense pain constantly tormented them.
If his experiment succeeded, his opponents' physical condition would steadily deteriorate during combat. The longer they stayed near him, the worse their condition would become.
"I've reviewed your experimental report. The Subtle Illness Extraction Technique has no effect on this condition, correct?" Orochimaru noticed the Chūnin's unusual state. He examined the man's perfectly normal lungs with curiosity.
"That's right, Teacher. Cancer cells are essentially normal cells produced by the body itself, so they can't be identified as foreign pathogens," Amemiya Kenichi nodded.
He had previously instructed the medical team to attempt cures for cancer patients, but none had succeeded. Early-stage cancers had a certain cure rate, while mid-stage cases depended on the patient's physical resilience.
Late-stage cancers had no successful cures, let alone terminal cases.
Of course, it could also be because the Ninja World's research into cancer wasn't very advanced.
"Continue. I want to see what you mean by 'late stage'," Orochimaru urged impatiently. This behavior was indeed strikingly similar to that of Hashirama cells.
Amemiya Kenichi nodded. If it had reached the late stage, the Chūnin was likely on the verge of death, beyond any hope of recovery.
Soon, as Kenichi continued to infuse Yang Chakra into the lung cancer cells, abnormal patterns gradually appeared in the Chūnin's lungs. Eventually, a cluster of irregular white pits formed on the lung surface.
This was a clear sign of the lung cancer cells taking over, now large enough to be seen with the naked eye.
"It takes too long, Kenichi. You need to improve this," Orochimaru said, shaking his head before nodding. The time required was excessive.
To achieve this effect, Kenichi had to continuously pour Yang Chakra for an extended period. How could anyone possibly have that much time to continuously channel Chakra on the battlefield?
It seemed this ninjutsu still had significant limitations, but it could be quite effective for ambushes.
Take his chain-smoking teacher, Sarutobi Hiruzen, for example.
"I understand, Teacher," Amemiya Kenichi said, scratching his head. Developing this ninjutsu was indeed challenging, but if they could overcome these hurdles, its potential would be immense.
However, if lung cancer cells could be stimulated by nicotine, what about cancer cells in other tissues? He couldn't possibly hunt them down one by one—that would be too tedious.
Amemiya Kenichi had an idea. In his previous life, when radiation was first discovered, it was considered a miracle substance. People even used radium in cosmetics.
Of course, later they learned that radiation caused cancer, and people began to avoid it like the plague.
So Amemiya Kenichi's plan was to find those radioactive elements from his past life in the Ninja World. If he could create nuclear radiation...
After reviewing the current experimental progress, Orochimaru left. Before departing, he instructed Amemiya Kenichi to record how long the Chūnin test subject survived and to document any symptoms.
Amemiya Kenichi didn't mind. Even if his teacher hadn't told him to, he would have done it anyway. After all, this was a rare Chūnin-level test subject.
After finishing his research, Amemiya Kenichi went to Ichiraku Ramen.
Ichiraku Ramen had been a staple in Konoha for years, witnessing the growth of countless ninja. Nohara Rin had even brought Obito and the others here when she was still alive.
Amemiya Kenichi occasionally ate here because the ramen was genuinely delicious, though it was a bit pricier than his usual spot.
He even suspected that the cheaper ramen shop's lower prices were due to its inferior flavor compared to Ichiraku's.
As soon as he sat down, Amemiya Kenichi noticed a ninja sitting two seats away. That distinctive hair instantly gave him away.
Kakashi.
Amemiya Kenichi glanced at Kakashi. He hadn't changed much, but these days he seemed to appear and disappear at will. Amemiya Kenichi figured he'd probably joined Anbu.
The Fourth Hokage, Namikaze Minato, hoped that Kakashi would recover by immersing himself in the Anbu's demanding missions. Judging by the results, it seemed to have had some effect.
"Kamui, huh?" Amemiya Kenichi clicked his tongue. The more he thought about it, the more he felt this ocular jutsu suited him perfectly. But right now, Kamui was split between two people.
Kakashi was easy enough to approach, but Obito was a different story.
Besides, the complete version of Kamui required both eyes, and they shared the same dimension. Thinking about it, Obito must have been bombarded with Kakashi's exploding tags and kunai while trapped in the Kamui Space.
When he looked at it that way, Obito seemed almost pitiful. And his devotion to Kakashi was undeniable—he hadn't even tried to reclaim his eye.
Kakashi remained expressionless. Amemiya Kenichi didn't want to force the issue, so he quietly finished his noodles.
By the time he was done, Kakashi had already left.
Amemiya Kenichi didn't mind. He picked his teeth with a toothpick and strolled leisurely toward home.
"Senior Brother Amemiya!" He'd barely taken a few steps when he heard a voice that made his head ache.
Anko Mitarashi was back.