9 Chakra

"Okay Ayumi, give him a crash course on the basics of ninjutsu. I will set up our camp and gather some firewood." Shimei said and went towards the tent.

"How much do you know about ninjutsu?" Ayumi asked curiously.

"Let's say that I wasn't paying attention during the lecture..." Aizen answered awkwardly. When he was reading Naruto manga in his former world, he never focused on the intricacies of chakra. He only cared about exciting things that can be done with it.

Ayumi sighed with a slight disappointment but decided to cover the absolute basics.

"You see, chakra is produced within the chakra coils that are connected to each chakra-producing organ, the energy circulates throughout the body in a network called the chakra pathway system. We can generate chakra and release it from our bodies through pressure points called tenketsu to perform jutsu." Ayumi explained patiently.

"Chakra is created when both physical and spiritual energy mould together. Physical energy is collected from your body and can be increased through training or stimulants, and spiritual energy is derived from your mind. It's much harder to enhance your spiritual energy as it requires meditation and experience. For example, repeatedly practising a technique will build up experience, increasing your spiritual energy and thus allowing more chakra to be created. The same cycle applies for physical energy, except the ninja needs to improve their endurance instead." Ayumi smiled and continued.

"Can you sense chakra in your body? Try it!" Ayumi said.

Aizen sat down on a flat rock in a lotus position and closed his eyes. He slowly gathered his physical energy, but couldn't generate this so-called spiritual energy. When he tried to substitute it with reiryoku, the energy became unstable. Aizen felt as if a thousand sharp needles pierced him from the inside. Volatile energy circulated through his body, injuring organs and everything on its path. He began sweating and spat some blood.

*Shit, this is bad. I must do something, or this is not going to end well!* He thought and started to think about a method to resolve the issue.

"W-what's going on!? Hey, talk to me!" Ayumi shouted nervously. She never saw something like this.

Aizen couldn't find a way to expel the rampaging energy without using kidō, but he didn't want to use it in front of other people, at least for now. He decided to coat his organs and chakra pathway system with a thick layer of reiryoku.

*That should do it for now. I must find a way to expel this energy somewhere.*

"I'm fine. I must have circulated my chakra incorrectly, don't worry about it." Aizen answered.

"If you say so. You scared me for a moment." Ayumi sighed and said.

Shimei finished setting up the camp. There were three sleeping bags inside the tent and a small campfire in front of it.

"Okay, I'm done. Let's train!" Shimei shouted.

When Ayumi went toward Shimei, Aizen quickly ran into the forest using shunpo.

"Ayumi, have you seen Aizen?" Shimei asked as he turned toward her.

"Yeah, he's ... " Ayumi said trying to find Aizen, but to her surprise, he wasn't here.

"I don't know where he went. Whatever, he will probably come back soon." She answered.

"Fine, we will start without him." Shimei said.

"Sure, but I won't go easy on you!" Ayumi replied with a grin on her face.

-----

Aizen quickly moved four hundred meters from the camp by continuously using shunpo, but that was not enough to get rid of the unstable energy.

He extended his palm and began chanting the incantation.

"Ye lord! Mask of blood and flesh, all creation, a flutter of wings, ye who bears the name of Man! Inferno and pandemonium, the sea barrier surges, march on to the south!"

"Hadō #31 Shakkahō!" Aizen said when he finished chanting. An orb of red energy formed in front of his palm and flew forward, collapsing trees in its way and leaving a small crater in the ground.

*It was much weaker than I expected. Looks like mixing reiryoku with physical energy is a bad idea when it comes to Kidō, but at least I was able to resolve the issue.* He thought.

Ayumi and Shimei didn't hear the small explosion as they were too absorbed by their training.

*Maybe pure reiryoku is too potent to be mixed with physical energy? It's worth a try.* Aizen attempted to form chakra once more, but this time he decided to dilute his reiryoku.

Aizen gathered his physical energy and slowly added the diluted reiryoku. The two powers fused and began flowing harmoniously throughout his chakra pathway system.

He moved a tiny amount of chakra to his finger and saw that a small flame appeared above it.

*Looks like my first chakra nature is fire. I can't say that I'm pleased with it. It may look impressive, but it's very impractical. The techniques aren't as fast and deadly as wind or lightning based ones. Earth and water provide much better protection and can be used to support your allies. However, there seems to be one benefit of using a mixture of physical energy and reiryoku compared to regular chakra. I can manipulate this type of chakra just as easily as I can control reiryoku.* Aizen thought.

Aizen covered his hand with a thin layer of reiatsu and began pouring more and more chakra to his hand. It suddenly caught fire, but he didn't feel any pain. He clenched his fist and gathered the fire around it.

*I wonder how powerful those flames are.* He thought.

He walked toward a tree and sent out a straight punch. The bark of the tree immediately caught fire. His fist went through the tree, leaving a charred hole.

*How should I call this technique? Maybe 'fire fist'? However, it's too dangerous to use. I would have to get close to the enemy. It resembles Rasengan or Chidori, all of those techniques should be guaranteed kill if they connect, but place the user in high-risk situations. It's not good enough.* He thought and decided to think about a technique that would be able to harm his opponents from range.

He extended his right hand and pointed the index finger at another tree. A small ball of fire appeared in front of his finger. The ball suddenly enlarged and shot forward, morphing into an arrow as it flew. The arrow reached its destination and ignited the tree. After a few minutes the tree crumbled to pieces, leaving only a few black, charred pieces of wood behind.

*I can freely change the shape and intensity of the fire. There's also no need for any seals, but I should probably add at least one or two seals before using this technique, or else they may think that there is something wrong. I should probably go back to the camp. It's getting dark.* He thought.

With a quick shunpo, he disappeared into the forest.