Naruto: Reincarnation With All Existence System

After the Elder demon bat told Ren to follow him, they went into an even deeper part of the cave. This part of the cave was completely devoid of light and now even with Ren's night vision, he couldn't see very well, and now he was mainly depending on the one-meter soul vision the soul path gave him. Then as Ren continued to walk farther into the cave even his one-meter soul vision began to become suppressed and now it was only half the range it would normally be. After this, the Elder demon bat and Ren continued walking even farther into the cave and now his one-meter soul vision only gave him blurry images and was only a radius of thirty centimeters.

"We are now at the location where you can begin testing. The first test you have will be getting attacked by demon bats and you have three days to be able to dodge their attacks for an hour straight. Now let's begin the test" - Elder demon bat

After the Elder demon bat said this Ren heard what sounded like small vibrations in the air. Ren almost instantly thought this must be the demon bats, so he tried to sense where the demon bats are. Then Ren saw a small figure appear in his one-meter soul vision, but since Ren only saw it when it was 30 centimeters away from him he couldn't dodge the demon bat and was attacked directly on the right side on his torso. Ren knew that if he activated one of his boosting jutsu he probably would be able to dodge the demon bat, but Ren knew that he would probably learn from this.

The next day passed without Ren making much progress in dodging the demon bats. The only reason it became slightly easier was that Ren's ability at sensing and agility became better. The main problem with dodging the bats was that Ren still didn't have enough time to react to the demon bats. Even though Ren knew that with his dojutsu his sensing would be a lot better he didn't want to use it for the same reason as not using his boosting jutsu. Then after a while, Ren began to focus on his hearing instead of trying to see with his one-meter soul and sensing the demon bats chakra.

After a few hours of just focusing on his hearing, Ren was now able to recognize the echo of the sound that the bat's wings made. Now that Ren could recognize the echo of the demon bat's wings he noticed that the demon bat's wings slowly became even quieter and now even with only focusing on his hearings he could barely hear the demon bat's wings flapping. As the demon bats continued to attack Ren, he remembered that when animals used echolocation they made sounds to tell how the sound waves interact with their soundings. So Ren decided that he would tap his foot and see how the sound interacted with his surroundings.

As Ren continued to do this for hours he slowly was able to tell the demon bats location with the echolocation. Even though Ren was now able to tell the demon bats location with echolocation he still wasn't experienced enough with it to always be able to tell the demon bats location. Then as Ren spent more time getting more experienced with echolocation he slowly was losing his stamina, and chakra because he kept using his chakra to heal his body. It was now the third day, and Ren knew this because of All Existence and he also knew that in total he had only dodged the demon bats for a maximum of 27 minutes. Ren wondered how he could get better at being able to detect the demon bats. The method Ren decided on was that he would stop making the sound with his foot and instead made sounds with his mouth.

Even though Ren slightly improved his method he knew that he still needed to do more if he wanted to be able to dodge the demon bats for a whole hour. The method Ren decided to do was use Shikotsumyaku to make small sharp bones come out of his body which would make small cuts off the demon bats and then they would drop some blood. Once the blood had dropped Ren would be able to detect it with his echolocation and then he slowly moved to where the blood dropped and then fused the demon bat blood with his blood using Sakon and Ukon's Kekkei Genkai.

The reason that Ren decided to fuse part of his bloodline with the demon bats was that he hoped that his body would begin to change his ear to be similar to the demon bat's ears so that he could use them for echolocation a lot better. Since Ren knew that his body wouldn't develop enough in a matter of fewer than 24 hours to become better at echolocation, he decided that he would have All Existence forcefully make his ears more similar to demon bat's ears. This cost Ren 5,000 points, but after Ren made All Existence do it he felt that he could now hear where the demon bats were very easy.

Now that Ren could hear where all the demon bats were going to attack him from he began to use this time so that he could train with the soft physique modification. The soft physique modification allowed Ren to move as Orochimaru did. Since Ren didn't have much experience with the soft physique modification it actually made him worse at dodging but after using it for a few hours it made Ren a lot better at dodging and now he could bend his body in inhuman ways.

Now that Ren had a better dodging method and had ears similar to demon bat's ears, he could now easily dodge the demon bats for longer than an hour. The only problem that Ren had with dodging the bats was that he was running out of chakra, but Ren solved this by using a mix of normal chakra, dark chakra, and star chakra. Now that Ren could easily dodge the demon bats he decided that right now he could use this to be able to minimize the flaws in his movement.

After dodging for what didn't feel like long for Ren he heard a much louder wing flapping and then Ren heard the wing a lot closer to him. Even though this demon bat's speed was a lot higher than the other demon bat's, Ren had gotten much better at being able to dodge and was able to barely dodge this demon bat. Once Ren dodged the demon bat he heard the voice of the Elder demon bat.

"It seems that you have greatly progressed in a matter of three days, you were even able to barely dodge my attack. You have passed the first test, now we will take a short break then begin the second test." - Elder demon bat