The improvement in Mumei's strength naturally made her very happy.
While delighted, Shinji also understood that this wasn't entirely due to the "Twelve Palaces".
In his view, Mumei, possessing "Yachihoko", should inherently possess strength far surpassing ordinary Mangekyo Uchiha.
It was just that the Uchiha clan was too wary of Mumei's "Yachihoko" before, only wanting to use Mumei as a weapon, never thinking of cultivating her carefully, resulting in her severe imbalance in skills.
In other words.
Mumei's current strength was what truly matched her level.
This also verified Shinji's viewpoint again: before becoming "Six Paths level" and completely transforming the body into chakra, the strength of control over the body directly related to whether a ninja could fully unleash their potential.
The "Twelve Palaces" he developed might not be the strongest taijutsu secret technique in the ninja world. But it was absolutely the taijutsu secret technique with the greatest effect on developing the body and tapping into one's potential!
After a simple warm-up, Shinji and Mumei began intense taijutsu combat in "Takamagahara".
Both had Uchiha bloodlines, both had transplanted Hashira cells to strengthen their bodies, and both practiced the "Twelve Palaces", so in terms of hardware conditions, the two were roughly equivalent.
In other aspects, Shinji's mastery of the "Twelve Palaces" was obviously deeper, and the insight of the "Six-Tomoe Rinnegan" was also above Mumei's Eternal Mangekyo Sharingan.
And Mumei's advantage was that her precise control over chakra exceeded Shinji's. This was not only a huge advantage in ninjutsu and genjutsu but also an advantage in taijutsu.
After sparring for a full hour, the two stopped.
Even with their physiques, an hour of high-intensity taijutsu confrontation was enough to plunge their bodies into high fatigue.
So one sat paralyzed on the ground, and the other fell directly to the ground.
Shinji, paralyzed on the ground, panted for a while and said: "It's not obvious during low-intensity confrontation, but once entering high-intensity confrontation, I always feel a bit uncoordinated in my body."
Mumei sat up: "Yeah, I also feel my body response getting slower and slower, and it's not entirely caused by muscle fatigue."
Listening to Mumei's description, Shinji recalled the fierce battle just now.
Honestly, due to being overly tired, his perception of his body obviously declined in the latter half of the battle, so he could only vaguely feel a trace of uncoordination, but he couldn't pinpoint where the problem was exactly.
It wasn't until he heard Mumei's description that he suddenly realized this uncoordination came from the body's response.
"So that's it..."
He stroked his chin, analyzing the reason.
The body's response speed is affected by multiple factors. Among them, muscle and ligament strength, blood oxygen levels, the degree of chakra stimulation on cells, etc., are all important influencing factors.
Using his knowledge of medical ninjutsu, Shinji began to rule them out one by one.
A moment later, he frowned deeply.
Mumei leaned in front of Shinji: "What's wrong?"
Shinji shook his head slowly: "Your perception is correct. After fully operating the 'Twelve Palaces' for a period of time, the body's response will slow down, but I thought for a long time and still can't figure out where the problem lies?"
Mumei helped Shinji analyze: "It shouldn't be a problem with our bodies. This response delay is obviously different from the slowing down caused by physical fatigue. Could it be some other reason?"
"Other reason?" Shinji was stunned at first, then his eyes lit up: "I know, it's the nerves!"
The limitation of thinking made him constantly consider whether there were problems in muscles, ligaments, bones, or organs. Reminded by Mumei, he thought of another factor affecting the body's response, which was the nervous system transmitting brain commands!
Getting up and pacing back and forth, Shinji sometimes frowned tightly, sometimes relaxed.
After a good while, he grinned: "I know what's going on. Mumei, thanks to you this time!"
Mumei pointed to herself: "Thanks to me?"
Shinji said: "If not for you, I might never have discovered this problem. If I encounter a real powerful enemy in the future, I might lose my life because of this!"
Mumei shook her head: "With me here, you won't die!"
Shinji smiled: "The point is not whether I will die or not, it's that we found a serious loophole in the 'Twelve Palaces'!"
Mumei asked: "What loophole?"
Shinji wiped the smile off his face and explained: "When developing the 'Twelve Palaces', I only considered the balance between various organs of the body. This point was originally fine, but I missed one item, that is, when any organ is stimulated by chakra, the nervous system will also be stimulated correspondingly..."
Pausing, he sighed: "And once we fully activate the 'Twelve Palaces', we will use chakra to stimulate all organs in the body. At that time, our nervous system will be stimulated several times, or even dozens of times stronger!"
Mumei suddenly realized: "I understand. If we operate the 'Twelve Palaces' at high intensity for a long time, our nervous system will be overwhelmed, and the brain's commands will be difficult to transmit to all parts of the body in time, so we feel the body's response slows down!"
"Correct!"
Shinji nodded heavily.
This subtle anomaly could only be discovered in time by Mumei, who mastered "Yachihoko" and had extremely precise control over chakra.
Like Shinji himself, as well as Ryuzetsu and Chino who served as Shinji's test subjects, none of them noticed it, always mistakenly thinking it was just normal physical fatigue.
Mumei hurriedly said: "Fortunately, fortunately. As long as we control the battle time, the 'Twelve Palaces' won't be considered problematic."
She didn't want to admit that there were loopholes in the "Twelve Palaces" developed by Shinji single-handedly.
Shinji shook his head: "It's not like that! The nervous system is actually more fragile than we imagined. Long-term excessive stimulation will cause irreversible damage to the nervous system. So this is not a problem that can be ignored. The 'Twelve Palaces' must be improved immediately!"
Saying this, Shinji started thinking.
Having found the crux of the problem, with his attainments in medical ninjutsu, improving it was actually not difficult. The real difficulty was how to solve this problem without weakening the power of the "Twelve Palaces".
Thinking back and forth, there seemed to be no perfect solution, only choosing to weaken the chakra stimulation. But once the chakra stimulation was weakened, the power of the "Twelve Palaces" would plummet.
"Unless..."
Shinji changed his thought and found a solution.
If the user's control over chakra was exquisite enough to precisely avoid the neural network when stimulating organs with chakra, then this problem could be solved.
It was just that in this way, the cultivation difficulty of the already difficult-to-master "Twelve Palaces" would increase by a large margin again...