I traveled the world collecting various types of human souls.

Well, saying it like this makes me sound like a dark wizard who uses souls as offerings for something.

But still, I gathered them through moderate means, by putting in the legwork! The easiest way would have been to collect them by killing humans! But I didn't want to do that!

I continued to search for and gradually gather the souls of those who had met death in various parts of the world.

I collected souls from the bodies of young people who died suddenly in accidents without even knowing how they died, from criminals who were executed for their crimes, from old people who died of old age after living a long life... and although I was reluctant, even from stillborn babies who died before they were born.

After traveling around the world and collecting the souls of the dead, I was able to learn about the structure of souls to some extent through investigation and research.

It might be a bit of a boring story, but I guess I should explain the nature of souls.

First, although souls appear to be a single entity, their internal structure revealed upon closer inspection consists of two opposing parts intertwined.

Like the Yin and Yang ☯, where each part consumes and merges with the other to form a whole?

One side is bright, light, and warm, while the other is dark, heavy, and cold. These two completely opposite qualities are tangled together to form a soul.

First, the bright part. This is the part I arbitrarily named the soul 魂 (hún).

This part was related to the innate nature of humans.

It was formed from a combination of innate personality, tendencies, and elements inherited from parents, and had a tendency to fly to the sky because it was basically warm and light.

Next, the dark part. This is the part I named the spirit 魄 (Pò).

This part was related to the personality formed after a human is born.

It was related to the personality completed through various memories and experiences created during the growth process, and had a tendency to sink to the ground and scatter because it was basically cold and heavy.

Thus, the innate nature and the personality formed after birth intertwined to complete a human soul.

If you ask how I knew about these two... I could say it was a fact I learned by examining various souls.

First, sample A. The soul of an old man who died satisfied after living a long life.

The soul of a human who survived for an incredibly long time compared to the average lifespan of humans in this era was significantly larger than other souls. Roughly the size of two of my fists when I transformed into a human. Moreover, the soul of someone who lived for over 80 years had an abnormal ratio.

If we consider the entire soul as 10, the ratio of soul and spirit in the old man's soul was about 2:8. A completely unbalanced form of soul.

Nonetheless, the old man's soul showed no significant abnormalities.

Next is sample B. The soul of a stillborn baby who couldn't even be born. Its size was very small, not even half the size of my fist.

The ratio of this sad soul was about 9.9:0.1.

Meaning, it was almost entirely soul.

A sad soul that remembered nothing but what it heard in its mother's womb.

Therefore, the spirit was not properly formed. How pitiful....

As for the other samples... In the case of a death row inmate, the ratio was 4:6, for a young person who died in an accident, it was 5:5, and most souls seemed to balance out to a ratio of 5:5 around the age of 20.

From there, as one ages, the size of the soul and the proportion of the spirit gradually increase, and if younger, the size decreases and the proportion of the soul increases a bit more.

Perhaps around the age of 20, the balance between soul and spirit stabilizes the soul, and as one ages and accumulates more memories and experiences, the proportion of the spirit in the soul increases, thereby breaking the balance of the soul.

So, is that why problems like dementia occur as one gets older? Hmm... This is quite interesting.

Then, what about elves, whose lifespans are more than 10 times that of humans? Do they maintain a solid balance between soul and spirit because they have a plant-like mentality? I'm not sure about this.

There seems to be a definite difference based on race, but that part requires more research.

I released the souls I had roughly researched, and many of them began to separate and drift away in various forms.

As the clustered souls slowly separated, the soul flew to the sky and the spirit scattered to the ground.

If I abbreviate it to four characters, it would be soul-flight-spirit-scatter (魂飛魄散). This is also why I named the two parts of the soul as soul and spirit.

Most of the released souls disappeared quickly. Hmm... Do ordinary souls disappear this quickly? If so, what are the souls that remain on the ground now?

That question was quickly resolved.

I had released all the souls I had collected, and most had disappeared, but one soul was still left.

The soul of a death row inmate. The soul of someone who had committed a crime, been tried, and executed.

The soul of the death row inmate, who continued to deny his own death even after leaving the body, did not scatter and remained. Investigating this soul, I could understand why some souls remain on the ground.

Mostly, after the body dies, the soul leaves the body and stays for a very short time before splitting into two and disappearing... Occasionally. A soul harboring strong negative emotions at the moment of death develops something like black soot, preventing the soul and spirit from separating and scattering.

Because the soul and spirit did not disperse as they should have, the soul continues to stay near the corpse, continuously denying its death while the black soot that has invaded the soul grows larger.

Eventually, the growing soot... completely blackens the soul, transforming it.

Such blackened souls become something difficult to call a soul anymore. It would be appropriate to call them evil spirits.

I conjured magic to bind the soul of the death row inmate that had turned into an evil spirit and began to examine the evil spirit.

The transformed soul. What is this black soot? Is the soul transformed by negative emotions? But it's strange for it to transform just by emotions...

It's like... something external is acting on it... No, it must be my imagination.

Anyway, I started to carefully scrape off the black soot covering the evil spirit using magic.

The damp and heavy fragments of the soul covered in black soot. This is... the spirit. It seems the fragments of the spirit were transformed by emotions.

On the other hand, the soul still maintained its form even in the state of having turned into an evil spirit. It seems this black soot transforms the spirit.

I infused a very small amount of magic into the scraped-off black soot, and the soot quickly dried up, shriveled, and scattered on the ground.

Hmm... Is magic the weakness of this black soot? Physical contact hardly affects it, but it seems weak to magic.

Now, I roughly know how to deal with the souls remaining on the ground. If I strip the black soot from the souls where the soul and spirit have not separated, they should separate on their own.

After separating the soul and spirit from the dead soul, scatter the spirit, and the soul... should I send it to the sky?

More importantly, where does the soul that flew to the sky go? The spirit scatters and disappears, but the soul that flew to the sky? Since the existence of souls, numerous intelligent beings must have died? Where did all those souls go?

Well, if I don't know where they went, I should track them.

I attached a faint thread of magic to the soul of the death row inmate and slowly floated it into the sky. Then, the soul gradually ascended into the sky.

The presence of the soul was so faint that it would be difficult to notice without paying attention, even for me. At least I could definitely know its location because I had attached a thread of magic.

Thus, I followed the soul that had risen into the sky and flew up, and only after reaching quite a high place could I see where the soul was headed.

Above the sky, a large number of souls were gathered so densely that it resembled a cloud.

The gathered souls varied in size, but for some reason, souls significantly larger than others split in half and divided into two, maintaining a similar size to other souls. Hmm. Do souls have a property to maintain a certain size? I'm not sure.

But looking closely at the gathered souls, there's something somewhat creepy about it. Watching these faint, round things gathered in large numbers..., I get the feeling that something is bound to happen if so many souls gather like this.

In the meantime, some of the souls floating in the sky fall to the ground. Souls so faint they're almost imperceptible pour down like raindrops, and I follow them down to the ground.

As if being drawn by something, the soul that fell from the sky drops onto a small cabin and seeps into it. It seemed as if something was pulling the soul in.

And inside that cabin... humans, to a fetus?

I flew back up to where the souls were gathering.

Hmm... It seems that there is some circulation of souls after all. Although a considerable amount has already gathered, it's still better than having no circulation at all.

Wait, if souls gather like this... what about the spirits? The spirits scattered on the ground? Do they just disappear? Or...

Do they seep into the ground... and go down...?

I had a very ominous feeling. How long has it been since souls started to appear? If so many souls have gathered, what about the spirits? The spirits scattered and seeped into the ground??

If the spirits, which turn black just by being exposed to negative emotions, and transform souls into evil spirits, seep into the ground in large numbers...?

If something triggers the spirits filled in the ground to develop soot? Then...

And most importantly, the ground is... a likely place where that child ran off to...

Not good. Yeah, not good. I feel like something big will happen if we don't hurry.

Indeed, souls require thorough management. If left alone, who knows what problems might arise!

But wait. If souls gather like this, and spirits scatter like that... what about those who died before souls existed?

Do their souls not exist? Or have they disappeared? What happened?

And... what about me? Does my soul exist within me?

Many questions arose... but for now, let's bury them...

I got the feeling that it's not good to think too deeply about it...