Next came Monsters.
To put it simply, Monsters are nothing more than mutated beasts.
Before becoming Monsters, they were Beasts.
At first, I had thought that "Monster" was just a nickname given to particularly powerful beasts.
But that was partially wrong.
Monsters are their own class of beings.
While they still have much in common with beasts—because they once were beasts—they are, in essence, something completely different.
Beasts are more like animals. They do not possess much intelligence.
Monsters are different.
Through mutation, they gain a kind of intelligence that still does not reach the level of humans, but is enough to make them stand out amongst ordinary beasts.
Not to the point that they suddenly speak or create their own language. But enough to make them far more dangerous and difficult opponents.
Since Monsters originate from Beasts, there is no real difference in their rank structure except for the names.
A Lesser Beast becomes a Fiend.
An Apex Beast becomes a Calamity.
But their actual power scale is vastly different from that of ordinary beasts.
A human at Stages Two to Four can defeat a Lesser Beast. But that does not mean the same human can defeat a Fiend.
The easiest way to explain it would be this:
The power scale between Monsters and humans is like the one between Beasts and humans—just shifted one full stage higher.
Fiends and Horrors are as strong as humans in the Fifth Stage.
Tyrants are on the level of humans in the Sixth Stage.
And Calamities are even stronger than Sixth Stage humans.
That alone shows the difference between Beasts and Monsters—and shows how dangerous Monsters really are.
So how does a Beast become a Monster?
It's pretty simple.
They mutate.
Or, to say it more accurately, they become corrupted.
The mutation is caused by corruption.
How do Beasts become corrupted?
Through Miasma.
Understanding what Miasma was made Rash's lesson far more exhausting than it should have been, because I didn't even know what Miasma was.
He had been visibly surprised when he found that out.
First of all, this world is vastly different from Earth.
And the one thing that creates that difference is Mana.
Mana is the cause of everything.
Why other races exist.
Why Beasts exist.
Why the Path of Mana exists.
Essentially—
Everything.
Rash didn't know much about it and said that this topic mattered mostly to scholars. Most people only learn the basics of it.
Still, from my knowledge of Earth, I was able to understand most of the logic behind it.
Everything in this world is created from Mana.
Even my own body.
The easiest comparison would be atoms.
Mana is like the foundational particle of this world.
The basis of everything.
And just as atoms can form countless things, mana, too, can exist in many different forms.
Water mana.
Is the same as hydrogen.
There are far more forms mana can take.
Fire mana.
Wind mana.
Earth mana.
And so on.
This mana can not be seen with the naked eye. Humans can only feel it.
It can be compared to breathing on Earth.
Normally, you don't really notice the air you are breathing in. But if you climb a mountain, it changes.
The higher you go, the thinner the air feels.
Mana works similarly.
Some regions are mana-dense.
Others are mana-sparse.
You can feel the difference the moment you enter such a place.
The arena itself is also like that, just on a smaller scale.
During the fights, with the crowd packed into the stands, the mana becomes thinner. But early in the morning, during my training, I can clearly feel that the mana in the air is denser.
Now, because mana is everywhere, there is another important point.
It can also exist in different types.
A fire-dense region.
That would be a place where there is a high concentration of fire mana in the air.
You would not be able to see the mana directly. But you would feel it. And you would also recognize it through the surroundings.
A volcano, for example.
You may not see the fire mana itself—
But you can see the lava.
The same principle applies to other mana types.
Water-dense regions would be places like seas or oceans.
It's pretty obvious.
And among all these different mana types—
There are also special ones.
Death mana.
And another name for death mana is Miasma.
Where does Miasma appear?
Around death itself.
Corpses.
That doesn't mean that if a single person dies in front of you, the area suddenly becomes a death-dense region.
It takes much more than that.
But what if many beasts die in a short amount of time in close proximity?
Then it becomes different.
The death mana released from all those corpses lingers in the environment. For a short period, the area can become a death-dense region, albeit a small one.
So what happens if a beast enters such a region and stays there for too long?
The death mana—Miasma—seeps into its body and eventually reaches its core.
This can happen through inhalation.
Drinking.
Or eating.
Once the Miasma enters the beast, it slowly begins to corrupt the core.
Every living being is formed from mana. That means every living being contains life mana.
Life mana is the natural counterpart of death mana.
When Miasma reaches the beast's core, the death mana begins battling the life mana within it.
And if the death mana wins—
It replaces the life mana.
This replacement should be impossible.
A living being needs life mana to remain alive. If its life mana is replaced by death mana, then logically it should become a corpse.
That is what should happen in theory.
But not in this world.
Instead, Miasma creates a paradox.
A living being without life mana.
A mutation.
The beast does not die.
Instead, it is forced to transform.
Its core changes.
Its mana changes.
Its pathways change.
Its affinity mutates—or is replaced entirely.
This creates a far more destructive affinity than the beast possessed before.
Not just the mana, the body changes as well.
It may grow larger.
It may develop unnatural marks or features.
Its fur or skin may change color.
A wolf might suddenly grow horns or wings.
The result is no longer simply a beast.
It becomes something new.
A Monster.
But what truly made people call these creatures Monsters was not just their appearance.
It was the mutation of their minds.
Miasma seeps into the mind, twisting instincts and behavior.
Not every Monster changes in the same way.
But all of them share one thing.
Death.
A Monster gains an instinctive urge to kill and destroy everything it encounters. It does not matter whether the target is a beast, a human, or even another Monster.
The Miasma desires death.
And the Monster obeys that desire, leaving destruction everywhere it goes.
But even that is not the worst thing about them.
The worst part is that Monsters corrupt their surroundings with the death mana mixed into their own mana. That means a Monster slowly poisons and destroys everything around it—even while standing still.
And once a Monster dies, it releases all the accumulated death mana from its core back into the surrounding area.
That, in turn, can create another death-dense region.
Which may then create another Monster.
An endless cycle of death and destruction.
At first, it sounded to me as if Monsters were some kind of immortal plague.
But that is not really true.
Because of one simple reason.
A beast must first become corrupted in order to become a Monster, and that process is not simple.
Some beasts resist it.
Sometimes there are no beasts nearby to be corrupted at all.
Even so, there are enough Lesser Beasts in the world that this still results in many Monsters.
But those are mostly just Fiends.
The weakest of the weakest.
Since higher-ranked beasts are much rarer, it becomes much harder for one of them to become corrupted.
That means there may be many Fiends—but only a small number of higher-ranked Monsters.
And that small number can, at least in theory, be dealt with.
There was one question that surfaced upon hearing about Monsters, and I didn't need Rash to find an answer.
Can Miasma only corrupt Beasts?
The answer to that was obvious.
No.
Miasma should not be limited to beasts alone.
It should also be able to corrupt humans.
I wasn't completely certain.
Not the full one hundred percent.
But at least ninety-nine percent.
There was no logical reason why it would only affect beasts.
Maybe humans have some kind of natural resistance or protection.
Maybe not.
I didn't know.
For now, the safest choice was to stay away from Miasma until I found a definite answer.
And the last thing about Monsters—
The transformation from beast to Monster is irreversible.
Once a Monster—
Always a Monster.