19. Mana, Miasma, and Monster Theory

"Hey, Mitoka. Monsters—how exactly do they come into being?" Shiro asked, suddenly turning to Mitoka.

"Come to think of it," Shiro muttered, "in the Filidia System I designed, there aren’t any monsters, are there?"

In Shiro’s system, the kind of "monsters" you’d see in games did exist—3D models, nothing more. Just digital assets for the game, so even if they looked hyper-realistic, they had no physical form. It was only now that he realized he’d never considered how creatures like those—biological entities unimaginable on Earth—could emerge or be controlled in this world.

"You're right, Shiro. We should start with what mana actually is," Mitoka said. "The implementation here is a bit more complex than your original magic design."

And Mitoka began her explanation.

First, in this world, there exists a particle energy called "Odo"—equivalent to fundamental particles in physics. In this world, it’s treated the same way as fundamental particles.

Furthermore, Odo is composed of two fundamental particles, each possessing a direction known as "spin."

The properties and names of Odo change depending on the combination of spin directions.

— Normal Odo: spin up, spin down — this state is called mana

— Strong Odo: spin right, spin right — this state is called magic power, generated by combining normal Odo with an awareness field

— Non-Odo: spin down, spin up — a post-magic manifestation state, resulting from consumption of magic power, willpower, and spirit magic; also referred to as used-up mana

— Reverse Odo: spin right, spin left — this state is called miasma. A corrupted form of mana, produced under specific conditions

"Magic works by converting the world's 'Constant Odo'—mana—into 'Strong Odo' through the conscious field generated by sentient beings, then transforming that Strong Odo into 'Non-Odo' via willpower and the consumption of spirit constructs. So, mana is expended when magic is used," Mitoka explains.

"Ah, so where does mana come from?" Shiro asks.

"Mana regenerates through the process of spirit constructs called mana spirits, which convert Non-Odo back into Constant Odo."

So it cycles: Constant Odo → Strong Odo → Non-Odo → Constant Odo.

"By the way, using powerful magic means the conversion from Non-Odo back to Constant Odo can't keep up. If mana supply dries up, the flow stops. Once magic power runs out, you can't cast spells anymore. That's why there's a limit on using extremely powerful magic consecutively," Mitoka continues.

"Right. So we can't just go wild with powerful spells."

"And the conversion from Constant Odo to Reverse Odo occurs through the reaction of miasma spirits, or via catalysts under specific conditions. This Reverse Odo is what we call miasma."

Mitoka goes on.

"More precisely, miasma forms when a certain concentration of mana reacts through a catalyst—usually what's known on Earth as methane."

And she adds, further:

When miasma remains in contact with non-sentient life—animals or plants without self-awareness (consciousness level below 4)—for extended periods, it generates a "gemstone core," transforming them into monsters. The creatures become enhanced and more aggressive. The denser the miasma, the stronger the resulting monster.

Larger monsters tend to become more ferocious, while smaller ones show no significant change in aggression. This is why tamers—trainers of monsters—typically use birds or small animals. Even the largest are usually no bigger than large dogs.

Once transformed into a beast, they exist as entities imbued with magical energy, and some beasts gain the ability to wield magic.

The "source of magical stones" continuously absorbs miasma, solidifying and growing. This becomes a magical stone; as its density increases, it crystallizes, becoming known as a magical crystal. In essence, magical stones and magical crystals are phase-transitions of miasma, solidified (solidified, crystallized). In solid state, they exhibit properties of magical energy accumulation. (Strong Odo + Solid Anti-Odo → Solid 2 Strong Odo)

Mitoka said, "Just be careful,"

"Gas-phase Miasma absorbs magical energy and forcibly converts it into non-Od, triggering magical depletion. Additionally, it poses a risk of mental deterioration—so please be careful not to come into contact with it," the warning stated.

When a monster dies, it leaves behind a corpse and magical ore—(in the case of animals), or magical sand—(in the case of plants).

Incidentally, direct monster generation by Miasma Spirits is known as a "Monster Pop." It begins with mana → miasma conversion, followed by generating a "raw mineral" in an environment of miasma plus methane.

Within the dungeon, the dungeon core uses this "origin of magical stones" as a substrate to generate any monster at will.

Outside dungeons, slimes typically form directly from the "source of magic stones." Depending on miasma concentration, magic beasts may also be generated.

"Hmm, I see—seems like there's actually a proper system in place here," Shiro mused, quietly considering whether to incorporate something similar into my own system.

"Say, I don’t see any Slimes around," Shiro asked, thinking aloud about their spawn conditions.

"True... probably can’t survive in this region, or maybe there aren’t many Miasma Spirits here," Mitoka replied.

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