Naruto: The God of Bloodlines

Yasu also shared with Rin some advanced medical knowledge and insights about the human body that he remembered from his previous life. These ideas made Rin reconsider how she could improve her skills in medical ninjutsu. 

Yasu explained concepts like acupuncture points, the body's meridian system, and the theory of cellular regeneration, which he noted was present in all human bodies and could be accelerated. From what Yasu understood, this was the foundation of Tsunade's ultimate technique, **Creation Rebirth**. 

Of course, Yasu knew that Tsunade could only use the **Creation Rebirth** after employing the **Strength of a Hundred Seal** and storing an immense amount of chakra within it. However, simply understanding these principles could enhance Rin's healing techniques and even help her learn to heal herself without using her hands. 

Yasu cleverly claimed he had learned these things from books he had come across and from overhearing members of the Hyūga clan discussing battles. He added that some of his insights were personal theories based on the books he had read. 

Thus, the three friends continued training together and improving their skills with medical ninjutsu. Obito, too, was making progress and felt happy to be closer to Rin, sharing a common interest in medical ninjutsu with her. 

Two more weeks passed, and Obito finally succeeded in reviving his first fish. Although it took him longer than Rin initially expected, she recognized that he had built a strong foundation and would soon be ready to move on to the next stage of training. 

Yasu had also shifted his training. Since he could go several hours without making a mistake in controlling his chakra for the **Mystical Palm Technique**, Rin decided to have Yasu heal smaller animals before returning to the challenge of reviving the large fish. 

Rin noticed that Yasu was ready for this new step and that sticking with the same training too long might actually hinder his progress. As she expected, Yasu didn't harm any of the small animals and managed to heal all the ones Rin brought to him. 

This meant that Yasu was already capable of healing himself and other shinobi. If it weren't for Yasu's fears, Rin believed he was more than ready to join the Third Ninja War and could greatly assist the village.

After this period of intense training, Yasu managed to increase the purity of his Sharingan to 25%. He was only 5% away from reaching the minimum purity required to activate the Sharingan.

Yasu's chakra reserves grew significantly, and his body became much stronger. He had increased the weights he carried to 800 kg on each arm and leg, for a total of 3200 kg. If not for these improvements, Yasu would have been hit by Obito's jutsus after increasing the weight load he carried.

This enhanced the efficiency of Yasu's training, and Obito also gained confidence, thinking that Yasu's increased difficulty in dodging his jutsus was due to Obito improving his own techniques. As a result, Obito genuinely made progress in his jutsu mastery.

Yasu was also training the sensory jutsu he had acquired whenever he could. He could accurately sense Obito's and Rin's chakra even with his eyes closed. Around the village, he could also sense the chakra of other shinobi, further improving his training.

The system's ability was so effective that it even worked passively. Because of this, Yasu could always sense when Minato was approaching, though this was primarily because Minato wasn't using the **Flying Thunder God Technique** at the time.

Thus, Minato remained unaware of Yasu's secret and the fact that he was training alongside his students. Minato simply assumed that Yasu was spending time with the pair during their training sessions.

Minato, relying on his instincts, noticed that Yasu had grown stronger. However, he had no way of knowing that Yasu could potentially defeat Obito. In fact, Minato believed that Yasu was currently at best at a genin level, which wouldn't be particularly useful to the village during this ninja war.

After the war began, Yasu started to get to know Minato better, one of his favorite characters when he used to watch the anime. However, it was precisely because Yasu knew Minato so well that he feared Minato would report his abilities to the Hokage if he found out.

In fact, this was exactly why Rin and Obito, after Yasu mastered medical ninjutsu, kept insisting that he reveal his new abilities to Minato. Yasu's fear wasn't going to war—it was being sent on an impossible mission as punishment and dying as a result.

Yasu didn't tell Obito that he also distrusted the Hokage. Perhaps even the Hokage could punish him by assigning him a suicide mission. Yasu knew very well about the horrible things the Third Hokage allowed and the atrocities he permitted Danzo to commit.

"Yasu, you don't need to be afraid of being sent on an impossible mission and getting killed. You've probably become one of the best shinobi our age in the village now. You can even beat me without using any jutsu."

"Now that you've mastered medical ninjutsu, you'll become even more valuable to the village. Minato-sensei can talk directly to the Hokage about your new strength and explain that you've only just acquired these skills, not that you've been pretending all along."

"You won't be able to fake being weak forever, Yasu. It'll be worse in the future if they think you were trying to avoid the war. If you learn more jutsu, you might even be able to escape from jonin-level shinobi from other villages," Obito said.

Yasu knew Obito was right. In the past, he could claim he wasn't strong enough and wasn't avoiding the war. But if he didn't reveal his strength now and go to the war, it would become the truth: he would be seen as someone who avoided the war and hid his abilities.

Yasu was also considering that Minato seemed genuinely trustworthy. A small favor like this wouldn't be hard for the future Hokage to grant. As for the fear of Danzo, as long as Yasu didn't become a jonin, Danzo wouldn't pay attention to him—Kakashi and Minato were already drawing all the focus.