The fighting on the battlefield could be as fierce as it wanted; it had nothing to do with Shin. He was immersed in his own life, and he couldn't have been more satisfied.
Every day, he kept an eye on the maid's progress in gathering chakra and gave her a few pointers. Then he went to the Uchiha Clan's Martial Arts Arena and did his best to guide the new generation. This was a long-term undertaking; he needed to gradually earn their respect and make an impression on them.
Usually, after guiding them, Shin would leave the clan grounds and practice various ninjutsu on his own. He would scatter kunai across the ground and then practice Flying Thunder God like crazy, improving his body's ability to adapt to space.
At the same time, he had begun researching the Rasengan, hoping to increase its power—ideally turning it into the Big Ball Rasengan. He also wanted to add a nature transformation to it, and hopefully figure out something like the Wind Style: Rasenshuriken on his own. Unfortunately, he hadn't made much progress yet.
Of course, he had also secretly tested Kamui's power, twisting everything before him to pieces and sucking it into another space. It was more than suitable as a trump card. Unfortunately, the side effects were too severe. Shin still remembered how, after that experiment, his Three Tomoe had burned with pain, nearly making him think he'd gone blind for good.
Fortunately, he recovered the next day, but he was still so frightened that he broke out in a cold sweat. Later, he figured it out: Kamui was a Mangekyo Sharingan technique, and it placed an enormous strain on the Sharingan. Even using the Mangekyo to cast it too often risked blindness, let alone with the Three Tomoe. That conclusion