Passed down knowledge

Getting up, I looked around at my surroundings. After nearly dying again, I wanted to cut my journey as short as possible so that I wouldn't have to spend another second on that mountain.

My eyes met a small decrepit wooden house, resting on a small outcropping of the mountain.

The ground looked solid yet I had a deep distrust towards whatever the mountain did or had to offer.

'This is 100% gonna collapse.' I thought as I carefully made my way to the shack, wary of the ground that might give in at any second and plunge me towards the depths.

I was so high up that the base of the mountain was not even visible anymore. A blanket of clouds or mist hovered just below the outcropping, shrouding whatever was below like gray stage curtains. 

Another thin layer of clouds hung above me trying to block out the endlessly bright sun yet only partially succeeding, causing my surroundings to be unusually bright with no objects being able to cast shadows, giving everything a deeply unsettling, dream-like feeling.

The house looked as though it had been battered by the mountain for centuries, only one bad storm away from being completely wiped away by the wind.

I walked inside and looked around the place. It only had one room with ripped apart futons and kitchen appliances all over the place. The floorboards creaked and the roof threatened to give under the pressure of the snow accumulated on top of it.

Dust clung to the floor like a carpet, giving the patches of snow and ice a dull shade of gray.

To my left, lay a toppled over bookshelf, its contents spilling out like the guts of a fallen soldier. The tomes were large, presumably very heavy and undoubtedly held knowledge I would not find useful.

It wasn't until I looked at the still standing fireplace that I remembered something I had long forgotten.

'How am I still alive?' I asked myself. 'Regardless of infection and starvation, hypothermia should have finished me off long ago.'

The frigid temperature always took a back seat in my mind as though nothing more than a slight inconvenience. Sure, total concentration may have increased my cold tolerance, but it doesn't explain how I survived in the last month even when I couldn't use it.

Pushing those thoughts aside, I knelt by the bookshelf and picked up one of the books. I blew the dust clinging to its cover and cracked it open. The ancient book sounded like its pages were getting ripped apart upon opening.

The inside confirmed that I had arrived at the correct destination.

Inside, the contents mostly resembled those in the old man's books. As a matter of fact, so did the other books, they all held borderline useless or redundant information I had no use for. Family register, basic sword stances and techniques, transaction ledgers, personal accounts of family members.

That last part intrigued me so I decided to keep reading. The book was only written about half way and it contained the handwriting of a few different people. Inside those notes lay anecdotes and information about past events.

A lot of these people seemed to have been demon slayers as many notes recall embellished heroic tales of family members valiantly fighting off demons. 

"Hyori of the aforementioned Koji family tragically passed away after a confrontation against an upper moon." I read out loud. "Upper moon? Didn't I fight someone like that before?"

I flipped the pages of the book and looked at the index, only to find nothing. I closed the book and picked up one of the remaining two. 

I held up a short, slim book titled "12 kizuki" and opened it.

The book contained information about a demon organization named in the title. This organization was home to the strongest demons in Japan and adhered to a strict hierarchical internal structure determined entirely by power. 

The ranks were divided into Upper moons and Lower moons both of which had six members. Their ranks were etched onto their eyeballs, with the highest rank being 1. Though, the book stressed that the difference between Lower moon one and Upper mook six was immense. The book also identified them as "The biggest threat to peace." Presumably there were others that were not mentioned.

'Finally something useful.' I rejoiced at the idea that I had finally read something worth my time and not having to sit through paragraph upon paragraph of mind numbing text.

I put the book in my sack and shifted my gaze towards the last book, one as small as my hand and about as thick as it too. 

'More junk.' I thought while opening it.

"Never fucking mind!" All it took was one glance at its contents to make me swallow my words. 

"As a disclaimer, this is a work of pure theory, continue reading only in hopes to broaden your horizons, not in hopes of gaining valuable knowledge." The book opened. "Recently, I pondered over the idea of total concentration. I tried analyzing its underlying mechanisms only to find nothing worth of mention that isn't already common knowledge, thereby, the following is a description of what you should already know.

We know that total concentration allows regular humans to gain supernatural strength, speed, agility and much more by absorbing the maximum amount of oxygen our body can take. This amount can be increased, increasing along with it the techniques effectiveness.

Taking this to the next level, there exists total concentration: constant which literally means keeping total concentration constantly on. This drastically increases lung capacity, physical stamina and strength thereby also increasing the effectiveness of total concentration.

Yet what lies beyond this level is unknown. Though I consulted many fellow scholars and even slayers, the overwhelming response I received was that total concentration is currently at its limits, that to improve total concentration, one must look towards the supernatural. A close minded argument, in my opinion.

Though I suppose they are deserving of some credit, total concentration as a technique has remained stagnant for millenia. I speculate that this is because in slayers' short lives, they spare no time to think much less practice improvements on seemingly flawless techniques. Though of course, this doesn't mean that some haven't tried, tried they have, failure upon failure they encountered. 

I am no different in this regard, my theory remains a failure to this day, not me, not anyone has managed to put it into practice. Yet I remain hopeful that one day someone will stumble across it and learn something from it. If, after reading thus far, you are still interested, I urge you to read forward where the explanation begins." 

I turned the page.

"The next logical step in this evolution is undoubtedly awareness. Complete, total awareness of one's whole body, down to their last composing particles. This, despite being the first, is undoubtedly the most impossible step. 

To achieve this, one needs to track the flow of oxygen through their own veins as though their consciousness stretches down and can peer through every inch of their body. 

Follow the oxygen to the cells, observe the process that is taking place, carefully observe everything.

This next step is where it gets highly theoretical.

By leveraging this newfound awareness, one can create a map of their own body, locating, with pinpoint accuracy every cell, every muscle, every nerve and every blood vessel. Then, using this map, one can begin to take control over every part of their body. This currently looks like the limit to what is theorizable without getting into the realm of fantasy. Though, theoretically speaking of course, with complete control over your own body, you could make yourself sweat with but a thought, cool down your internal temperature, and presumably, control your own blood flow.

I understand that the benefits of this technique are far outweighed by the years if not decades of constant practice it would take to master. Yet I urge you to give it a try, once mastered, if it even can be mastered, the possibilities are quite literally endless, the only inhibitors are your understanding of the body and your imagination." Thus the book abruptly ended after only a few pages.

I stood there in a stupor, I expected the books to be an upgrade to total concentration, which is why I was so excited, yet reading pages of theory that had never been put into practice was a little disappointing. 

Regardless, my excitement remained. Awareness and control seemed to be the two main components, one of which I was already good at. My awareness over my own body had been steadily improving since I began using total concentration, only recently making a big leap close to what the book described.

'Still, what this guy describes is borderline supernatural. Well, breathing oxygen in a weird way also gives you superhuman speed and strength so I can't really complain.'

Thinking thus far, I decided to give the old man's take on total concentration a shot before dismissing it. 

'Maybe this can give me some answers too.'