As Tatsu walked towards the city, he activated his Tenseigan and checked his vision.
"Wow, so this is how the world looks with Tenseigan, huh? Honestly, it's incredibly intricate and detailed."
As Tatsu looked around, no wall, no obstacle could stop him. He spanned distances, seeing everything within a 100 km radius in 360°. When he focused on something, he could even see its cellular structure. While Tatsu was enjoying this, he suddenly stopped and looked at the city. There was no sound in the city, but Tatsu knew with his Tenseigan that there were 20 people in the city, and their chakra levels were too high to be civilians. Tatsu ignored all obstacles and looked directly at their faces.
"Well, well, there are still Kaguya clan members in the city. But they might be decent. The strongest among them is a jonin. Since I've come to the Naruto world, I should start shedding blood and taking lives," he said and walked towards the city.
When he reached the city gate, two Kaguya clan members of chunin level standing on either side of the gate jumped in front of him and started mocking him.
Kaguya Clan Member 1: "Kekekeke, look at this, another sack of meat has come. I told you, if we stay silent, they'd think we've left and come here."
Kaguya Clan Member 2: "Yeah, it seems you're right. But this one is mine. You already killed the last one," he said and attacked Tatsu, thirsting for blood.
Of course, Tatsu had seen them with his Tenseigan but did nothing. From both the anime he had watched and the memories of this body, he knew that the Kaguya clan liked to share the kill. So, he had predicted that they would attack him directly without informing anyone.
As Kaguya Clan Member 2 lunged at him, Tenseigan sprang into action, analyzing all his movements and dodging his attacks.
Kaguya Clan Member 2 became frustrated with Tatsu dodging all his attacks. He drew two bones from his body and threw them from different directions. As Tatsu dodged these, Kaguya Clan Member 2 infused chakra into his legs, appearing right in front of Tatsu. Starting with an uppercut from below, he attacked, but Tatsu caught his right hand with his left hand, then infused chakra into his right hand just like he did to his legs, piercing his body with his hand and killing him.
The other Kaguya clan member watching this was shocked, but setting his surprise aside, he was about to attack when Tatsu suddenly appeared in front of him and killed him with a skull-crushing punch. Tatsu took a few steps back and took deep breaths, thinking to himself.
'Damn, I killed them in the heat of the moment. I just killed two people.' Tatsu fell to the ground, taking deep breaths, realizing for the first time what it felt like to take a life. It was horrible. Just a few hours ago, he was an ordinary university student living in the modern world, but now he had killed people with his own hands. They might have been murderers, even sociopaths, but they were still human.
While Tatsu wrestled with these thoughts, another Kaguya clan member arrived. Seeing the situation, he looked at Tatsu. Noticing his deep breaths, he understood; an ordinary person often reacted this way after their first kill. He had seen it before on the battlefield, but what he didn't understand was how someone who had just killed for the first time could have taken down two Kaguya clan members. Then he saw Tatsu's eyes and immediately attacked. Feeling the nobility and power from those eyes, he decided to kill him before he could grow stronger.
Tatsu was still taking deep breaths but saw with his Tenseigan that someone else was coming. As the person attacked, he used Shinra Tensei without thinking, tearing him apart. After a few more deep breaths, he gathered his thoughts and stood up.
'Yes, I might have killed people, but I did it because I had to. Otherwise, I would have died,' he consoled himself. There was nothing he could do now except avoid taking unnecessary lives.
He immediately entered the city, rummaging through some shops under the rubble. He ate a bit here and there, then grabbed a bag and filled it with as much food and water as possible. He then entered another shop, took some unworn clothes, and grabbed some money. It wasn't much, but better than nothing. After that, he went outside. It took him an hour to gather and eat. During this time, he stayed away from the Kaguya clan.
When he went outside, he entered the Tenseigan Chakra Mode and rose into the sky. At first, he planned to spend the night there, but seeing the 20 Kaguya clan members, he changed his mind. But there was one more thing he had to do before leaving.
Tatsu flew to a central point where he could see the entire city. Then, spreading his arms wide, he consumed all his chakra except 10% of it, and shouted, "SHINRA TENSEI!" just like Nagato did to Konohagakure in the canon. Suddenly, an incredible repulsive force spread from the center in all directions, wiping out the entire city and the Kaguya clan members, turning the whole city into flat land.
Hovering in the air, Tatsu marveled at what his power had done and felt a sense of satisfaction. He had three reasons for doing this: first, he wanted to kill all the Kaguya clan members; second, he wanted to test the extent of his power; and third, it was incredibly cool. But then he stopped and started to think.
"Just a moment ago, I was trembling because I killed some people, and now I feel nothing. I wonder why?" At that moment, the system spoke.
[Ding! The reason is the Yin Chakra your Tenseigan has given you. The Yin Chakra has strengthened your mind, allowing you to better adapt to such situations.]
Tatsu was surprised to hear this but quickly felt happy. Strengthening his mind was crucial, especially in this era of the Naruto world. He knew that wasting time on this could get him killed. Then he asked the system:
"System, how much progress have I made on my task to unlock the next world?"
[Ding! From now on, the number of people the host needs to kill is 35 Genin level shinobi and 6 Chunin level shinobi.]
Tatsu nodded, then flew to a forest near the nearest city. He needed time to think about what to do next and to spend the night.