Total Concentration Breathing Technique

After receiving treatment in the infirmary, I rested for a few hours and then went home. The nurse told me not to take painkillers as they might hinder the healing process.

Since she seemed to use magic, I agreed without much problem.

Back at my house, I sat on my bed, lost in thought.

On my first day of school, I met some interesting people and also joined the fight club.

Thinking about it, one single day here was more exciting than my entire past life, if you disregard the time I spent resisting being isekai'd.

Looking at my body wrapped in bandages, I sighed.

"One week…"

That was the time it would take for my body to fully heal. In my past life, even several months would have been insufficient.

After my fight with Seta, I noticed some interesting things.

Although we are humans, I noticed that Seta's strength was much greater than the fighters from my past life. He also seemed to have better control over his body.

Fighters from my past life definitely couldn't defeat him.

If Seta is already that strong, what about Ippo? Or even the other members of the club?

I knew this world was different from the one I lived in. But I didn't expect that even the humans would be more powerful.

"The human body of this world may not have the limiters like those of my past life? If that's the case…"

This could be the case.

Humans are the only race capable of reincarnating as devils without losing their high reproduction genetics. The same must happen with humans who reincarnate as angels. There's also that group of heroes who are no weaker than the leaders of these great factions.

I remembered that as a human I could also become a Mage.

But after thinking a bit about this option, I decided to discard it.

With my body, being a mage wouldn't be a problem. But it seemed like this body was more suited to be a martial artist. At least that's what I noticed while fighting.

I have inherited Yan Qing's talent for martial arts!

This was the best news I could have had.

I don't know if I will be able to replicate his powers, but with his talent alone, it wouldn't be a problem for me to reach the level of Sairaorg Bael.

Of course, reaching Sairaorg is still a distant dream.

I have one year until the plot actually starts, and I don't believe I can reach him in just one year. At least not with conventional methods.

Machio told me that when I recovered, he would show me the areas that only club members can access.

I hope there are some books on martial arts in that place, or even training methods. I wouldn't mind asking Seta or Ippo to teach me.

But I noticed that both seemed well-versed in a single style.

Although I haven't seen Ippo fight or train, I knew he was a boxer.

And Seta seemed to be a mix of boxing and Muay Thai.

Using boxing as a base would be good. But that's just it.

If I encountered an opponent who immobilized my hands, how would I fight against them? If I lost my arms, how would I fight?

I needed to be versatile.

"I almost forgot about that…"

While thinking about martial arts styles that would be interesting to learn, I remembered something important.

Breathing!

Yes! Breathing.

I noticed that breathing in this world seems to be of extreme importance, and it gave me some ideas.

This is a magical world with many possibilities.

And after the death of God… things became even more chaotic not only for other races but also for humans.

Issei showed that he was capable of doing the impossible.

And if he could, so could I.

I would bring to this world a breathing technique.

More specifically, Total Concentration Breathing!

With the death of God, many things became possible, so I should be able to use this technique from another world. There was nothing stopping me from using it.

Total Concentration Breathing is an esoteric breathing technique used by Demon Slayers.

This breathing technique involves expanding the lungs to take in as much air as possible, accelerating blood flow and heartbeat while increasing the body's internal temperature, resulting in more excited bones and muscles.

A simple technique, but with various benefits.

If I mastered this technique, I could match the best descendants of heroes.

Not to mention the cardiovascular improvement.

This technique would allow me to have superhuman strength, speed, endurance, durability, resistance, and the mental abilities necessary to keep up with my body that would become superhuman. Even my thought process would become faster, allowing my reaction time to improve.

This is also a technique whose only limiter is its user, as it continuously strengthens them.

Thinking about all the benefits of this technique, I decided to practice it.

Despite the difficulty, it seemed to fit me perfectly. And the way to train it was not complex.

The first thing I needed to do was to improve my lung capacity.

"Tomorrow I will wake up early and run with all my might."

Even with my injuries, I couldn't just stay at home relaxing. There were many things I wanted to do, and learning this technique would be my first step.

"I remember Tanjiro also practiced holding his breath. As well as meditating to help with concentration. Alright, I'll do all of that."

Having decided my next steps, I lay down in bed and fell into a deep sleep.

Today had been a tiring day, and I needed to rest.

…

After a long and painful night of sleep, I woke up.

Well…

Not as I expected.

I tried to get up from bed and the moment I put my feet on the ground, I felt an unprecedented pain.

"Is this the post-training soreness they talk about?"

My muscles were all tight as I dragged myself to brush my teeth and change clothes.

After spending half an hour to change clothes and brush my teeth, I had my breakfast and went for a run.

Yes… my body was sore, but that wouldn't stop me from training.

On the empty street, I took a deep breath and started to run at a slow pace, accelerating as my body warmed up. Due to my injuries, I decided to alternate running.

I would run intensely for three minutes and then walk for one minute.

I decided to follow this method for a full hour.

I remember that this running method was used by professional runners in my past life to improve lung capacity. As I was in a magical world, this method should be even more effective.

While running, I stopped at a pawn shop.

The reason?

I was looking for gourds that could help me in training.

The training process for the breathing technique wasn't just about improving lung capacity. It required blowing into a special type of super-durable dried gourd. The goal is to blow the gourd with enough force to make the gourd split.

And as I progressed, I would switch the gourd for a larger and more resistant one.

Unfortunately, the gourds they had at the pawn shop were just normal gourds.

At least their sizes were decent, so I ended up buying them.

I made sure to ask the shopkeeper if he could order some durable gourds for me. Initially, he seemed hesitant, but after I gave him a stack of money, he promptly accepted.

"Money really is a superpower…"

Except for the pains in my body, I had no trouble maintaining speed while running. I noticed that I would need to run with more intensity if I wanted to train my lungs.

"I'll buy some weights to tie around my legs, that should make it more difficult."

I returned home and went to the computer to do some shopping.

There were a few hours left until the start of classes, so I could freely browse the internet.

Besides making some purchases, I checked the day's news.

Upon checking the news, I noticed an article reporting the disappearance of some children. Seeing the location where the children disappeared, I realized that the likely culprits were the Fallen Angels.

"…Are they already making their moves?"

"Either way, I have nothing to do with this."

If I had enough strength, I wouldn't mind helping to find the missing children… no! At this point, those children must already be dead.

The Fallen Angels are after people with Sacred Gear to extract and use them for their own people. Even if I had enough strength, I couldn't bring those children back alive. At most, some corpses.

I was reminded that this world is far more dangerous than the one seen in the anime.