I Was Mistaken for a Saint in a Dark Fantasy

Blister Plague. Red Death. Black Plague. Curse of Decay. Bone Melt.

These were the names for Smallpox, Scarlet Fever, Black Death, Leprosy, and Bone Tuberculosis in this world, respectively.

Besides those, malaria was called the southern fever, and the Cinchona Tree was called the Tirun Tree.

In this way, this world sometimes called the diseases I knew by different names.

After realizing that fact.

The first thing I did was the task of translating the names of this world’s diseases into the ones I knew.

And in that process, I discovered a rather peculiar disease.

Demon Disease.

A disease that, instead of getting better with healing magic, only grew worse.It couldn’t be treated with healing magic or medicinal herbs, and there was no way to cure it other than praying to a god. It was the end-game disease of this era.

Immediately after hearing about it, I confidently delved into the literature.

’It must be something like cancer or a rare disease, right?’

Just as Smallpox was the Blister Plague and Black Death was the Black Plague, I thought Demon Disease would also be another name for a disease I knew.

As a result of compiling all the Demon Diseases recorded in history.

I fell into confusion.

’What the heck is this.’

The first historical case I saw was the story of a certain marquis.

— A lump grows from the body. The lump grows larger with healing magic.

At first, I thought Demon Disease was cancer.

But the next case was strange.

— A severe fever, enough to make the body boil. (Estimated around 40°C)

’Huh? A fever?’

Cancer generally doesn’t present with fever.

Of course, something called tumor fever exists, but that’s a rare symptom that only appears in stage 4 cancer.

Cases exceeding 40°C are extremely rare.

In other words, it led to the contradictory conclusion that Demon Disease was a ’tumor disease accompanied by a systemic high fever.’

The problem was that the symptoms of Demon Disease didn’t end there.

— The heart suddenly stops.

— The bleeding won’t stop.

— The entire body turns black.

.

.

.

Demon Disease had no consistency from patient to patient, and every type of symptom a human could experience was recorded.

Even after that, whenever I had time, I tried to figure out Demon Disease.

And the answer came to me relatively recently.

— ”Come to think of it, long ago, the Pus Plague was sometimes confused with the Curse of Decay. They were separated as time went on, though.”

According to my teacher, hundreds of years ago.

People couldn’t distinguish between Smallpox and Leprosy, so they called them both the Curse of Decay.

But as time passed and the Healing Arts developed, it was revealed that the two were different diseases.

Thus, Smallpox came to be called the Pus Plague, and Leprosy the Curse of Decay.

The moment I heard that historical fact, I was able to realize my misunderstanding of Demon Disease.

A world where medicine was less developed.

A world setting where all medical standards were determined by healing magic.

In such a world setting, they were calling ’all diseases’ that, far from being cured by healing magic, were actually worsened by it, Demon Disease.

In other words, Demon Disease was something like an aggregate of all undiscovered illnesses, including cancer, autoimmune diseases, and genetic diseases.

So, classifying those Demon Diseases one by one had been my recent interest, but...

’Freya has Demon Disease at this timing?’

Freya was showing symptoms that corresponded to Demon Disease.

’Should I be happy about this or not?’

Looking back on my life, it had always been like this.

As soon as I finished researching and creating Quinine at eight, my father contracted malaria.

After I returned from gaining experience in the Red-Light District, my mother and Fried were almost in danger.

And now that I’m researching Demon Disease, Freya gets Demon Disease.

It definitely fits the convention of the Misunderstanding Genre...

’I didn’t cause this, did I? Right?’

I just have good timing, right?

Surely I’m not like a certain boy detective, bringing death with me wherever I go?

...Please tell me I’m right.

That’s not what’s important right now.

’First, I need to classify this Demon Disease.’

As mentioned, Demon Disease is not a single illness.

Cancer, autoimmune diseases, genetic diseases.

The general term for all illnesses that are not cured by healing magic is Demon Disease.

Naturally, to treat a disease, you must first identify it.

So, to treat Demon Disease, I need to figure out exactly what disease this is.

’Let’s organize Freya’s symptoms.’

High fever, non-blanching erythema, conjunctival injection, dry mucous membranes, splenomegaly.

And crucially, it worsened after applying Minor Heal.

’The principle of Minor Heal is strengthening regenerative power and immunity.’

A list of diseases that could be worsened by Minor Heal formed in my mind.

Cancer, autoimmune diseases, rheumatism, anaphylaxis...

Among them, I filtered out only the diseases that could cause a high fever of over 41°C.

That alone narrowed down the candidates significantly.

’Adding her medical history of frequent colds and the fact that she’s a 14-year-old girl...’

Cytokine Storm.

Yes. This is the most likely culprit.

When the immune system fights a pathogen, the body raises its temperature to create a favorable home ground.

This way, germs vulnerable to heat can’t exert their strength in the heated body and are unilaterally subjugated.

— What a cheap way to play!

The brain, which normally keeps a limiter on body temperature, releases that limiter for this moment, allowing the temperature to keep rising.

The problem occurs when the immune system, while fighting the germs, occasionally goes berserk.

— I will no longer be under your control!

Normally, the immune system should raise the temperature moderately, but drunk on its own power, it raises it without limit.

The brain, which should control this, has already released the limiter.

This way, the fever rises without bound.

As a result, the brain gets cooked like sous-vide, and the person dies.

This phenomenon is called a Cytokine Storm.

’It’s like setting your house on fire to catch a single thief.’

Well, strictly speaking, it’s more complicated, but that’s the gist of it.

’Applying Minor Heal in this situation just made the symptoms worse.’

The pathogens inside Freya’s body are probably all dead by now.

Due to the high temperature and two rounds of Heal, they’ve likely vanished without a trace.

But in exchange, her body temperature is now approaching 42°C.

I needed to lower her temperature right now.

Finishing my thoughts, I called to the priestess who was constantly wiping away cold sweat with a handkerchief.

”Sister.”

”Y-Yes!”

The priestess’s shoulders flinched.

”Each time you cast Heal, the child’s condition surely worsened. Correct?”

”Yeees...”

”Then why did you continue to cast Heal?”

The priestess’s face turned pale.

”Th-That’s... her fever wouldn’t go down... I thought it was because I didn’t have enough divine power...”

”If your divine power is insufficient, it has no effect, not an adverse effect.”

”...Yes, that’s right.”

”Then if the patient’s condition worsens, you should stop and call a superior. Why did you keep trying on your own?”

”I’m sorry...”

”Hmm. You must have learned about Demon Disease in school. Are you perhaps an apprentice priest?”

”I... I’m low-rank.”

Damn it.

As expected of a dark fantasy world brimming with romanticism.

Of all people to send on a house call, they send a resident doctor.

No, wait.

Come to think of it, even in the 21st century, they sent interns to local emergency rooms.

...Damn it. Even when the world changes, the tiresome jobs are for the subordinates.

”It was late at night and a house call, and you heard it was a cold patient, so they must have sent you.”

”Yeees...”

It’s not that she didn’t know about Demon Disease.

Her lack of actual combat experience just meant the knowledge didn’t surface when needed.

It’s a common phenomenon seen in resident doctors who have only recently been assigned to the field.

’Tsk tsk. She must have come thinking it was just a cold patient. How flustered she must have been when it suddenly turned into Demon Disease.’

Her mind is probably completely blank right now.

To use an analogy from my previous life, it’s like an intern on night duty alone when a patient stabbed in the heart is wheeled in on a gurney.

The patient is dying, and the professor isn’t answering their phone.

Then the heart stops, so they just start doing heart massage.

On a patient with a hole in their chest, no less!

On top of that, the patient is from a prosecutor’s family.

I think even I would have cried if I were an intern.

In fact, I did.

Tsk. What a cripple I am.

It was a miracle I managed to sort that out back then.

Come to think of it, it was because that professor helped me out that I got roped into choosing the Thoracic Surgery Department.

Why did I do that? I should have just gone into the Radiology Department and secured a good work-life balance.

I keep getting sidetracked.

In any case, what the Low-rank Priest did was a major incident on that scale.

A noble young lady, and a patient with Demon Disease at that, and she didn’t even notice properly and cast Heal repeatedly.

Thanks to her, the Demon Disease had gotten much worse.

”Sister.”

”I’m sorry. Please, forgive me, Lord. I still have daughters...”

Oh my, you have daughters too.

To think she was a working mom.

Judging by the wrinkles, she seems to have some age.

And yet she’s still a Low-rank Priestess...

’A late bloomer, perhaps.’

Well, it was a common sight in medical school too.

There were older brothers and sisters who entered medical school after turning 30.

”I understand.”

I calmed the sobbing priestess.

As a family member, I wanted to be angry and argue, but that wouldn’t change anything.

The priority right now is Freya.

And to treat Freya, I need the priestess.

’If an emergency happens, I have to keep her alive by at least casting Heal.’

Although the Heal made things worse, it is still essential in an emergency.

Because it increases not only immunity but also life force and regenerative power, it can delay multiple organ dysfunction syndrome.

The reason Freya is holding on now is because the Heal that sent her immunity into overdrive also strengthened her life force, allowing her to endure somehow.

Therefore, this Low-rank Priest was no different from Freya’s life insurance.

”I was wrong... I was wrong...”

But in this state, I couldn’t even use her as an assistant, so I needed to calm her down first.

Maybe I should try to lighten the mood with some small talk.

”Please calm down. You mentioned you have daughters, how old are they?”

”They’re 14 and 16... and unlike me, they’re both good at their studies, have good personalities, ah, the older one has been going through puberty lately...”

”Yes. That’s good.”

I cut off the priestess’s rambling.

”As it happens, my younger sister is 14. If you think of Freya as your own daughter and do your best to treat her, wouldn’t that be enough?”

”...Please, just spare my daughters!”

No, how was that translated?

What I meant was for her to wring out everything she’s learned from her brain.

Did she think that if Freya died, her daughters wouldn’t be safe either?

There’s no way I would do that.

...Although I can’t say the same for my father.

Hmm.

Come to think of it, I don’t think this family would be safe if something happened to Freya.

”...Please calm yourself. What I mean is, haven’t you learned anything about how to manage the symptoms of a Demon Disease patient?”

The priestess shook her head.

I figured as much.

The treatment guideline for Demon Disease that I know of is to just leave them be and pray.

Don’t cause them needless suffering by casting divine magic; just follow hospice procedures.

What if they don’t die?

Then the prayer has reached a god.

’I asked just in case. I guess I don’t need to be discreet anymore.’

From that moment on, the priestess was relegated to the role of a Heal Totem.

I’m truly sorry for seeming to ignore an expert’s authority.

But a family member’s life is on the line here.

I immediately began to formulate the procedure to treat Freya in my mind.

’First, I have to kill her immunity.’

The cause of a Cytokine Storm is excessive inflammation.

Therefore, this inflammation needs to be suppressed.

And there was a separate medicine for this.

’The steroid... here it is.’

Fortunately, I had a steroid in my bag.

Steroids are drugs that reduce inflammation, made by grinding pig adrenal glands.

However, there was a minor problem with this steroid.

The yield from adrenal glands was absolutely terrible.

This is because, unlike insulin, steroids are not a hormone stored anywhere.

It’s a hormone made on the spot whenever needed.

Because of this, even if you cut open a pig, you won’t get even a rat’s tail worth of steroids.

To give you an idea of how little, you’d get about 1g of steroid from mashing about a ton of pig adrenal glands.

Because of this horrible and desperate yield, steroids were a precious medicine that even I had little of.

’One 1g ampule.’

You could say that thousands of pigs are condensed into this small ampule.

No joke, this single bottle cost as much as the research fund I had donated to my teacher this year.

But,

’What am I thinking about.’

There was no hesitation.

She’s my only younger sister.

Earning money. Trying to achieve success using the Misunderstanding Genre.

In the end, it’s all to make my family happy.

If I save this medicine now, where would I even use it?

I took out a syringe.

Without delay, I tied a tourniquet around Freya’s slender arm.

Over the bluish vein that popped up, 1 gram of medicine, a compression of one ton, slowly began to seep in.

’Please, hang in there.’

Normally, you don’t administer 1g of steroid at once.

The pill that allergy patients usually take is 10mg, which is 0.01g.

So right now, I’m administering 100 times the amount those people take, all at once.

But there was a reason for this as well.

’I have to go with pulse therapy.’

It was a drastic prescription to forcibly shut down the rampaging immune system by hitting it with a high dose of steroids all at once.

It was a crazy act that could normally stop the heart.

But right now, saving the brain was the priority, so I had no choice.

’If her heart stops, I can just use Heal or perform CPR.’

But if the brain is cooked, there’s no hope.

So, I had no choice but to take this gamble.

5 minutes.

10 minutes.

Over 15 minutes, I administered the entire 1g.

Slowly, as slowly as possible, controlling the speed by hand.

It was a last-ditch effort to put as little strain on the heart as possible.

’Please...’

I removed the syringe and pressed a piece of sanitary cloth firmly onto the injection mark left on Freya’s arm.

”Sister.”

”Y-Yes!”

”Please bring a towel soaked in cold water. And also some boiled and cooled water. We can’t let her get dehydrated.”

”I understand!”

The priestess, who had been promoted to my assistant at some point, scurried out of the room.

I placed my hand on Freya’s forehead.

It was still hot.

’Of course.’

Steroids aren’t magic.

It’s not like the fever will drop instantly just because I pushed the syringe.

It takes at least 2 hours, maybe as long as 4, for the effect to start showing.

I should know that fact rationally, but...

’Please...’

My mind was filled with anxiety.

Just then, I heard Freya’s weak voice.

”Older Brother...”

”What is it?”

”Are you there?”

”Yes. I’m here.”

I took my younger sister’s sweat-drenched hand.

The trembling hand of a fourteen-year-old girl.

An age old enough to know what death is, but too young to accept it.

”It’s okay.”

I squeezed her hand tightly.

”I’m here.”

”...”

”What did I say last time, when Fried was born and got sick?”

”...I believe in you, Older Brother.”

”That’s right.”

After hearing my answer, the strength in Freya’s hand lessened slightly.

An hour passed since then.

41.0°C, no change.

Two hours passed.

40.7°C.

It went down a little.

Three hours passed.

41.0°C. It went back up.

’Damn it...’

There’s no sign of the fever breaking.

Was the steroid dosage insufficient?

Or is the immune system, which went berserk due to the Heal, too strong?

I clicked my tongue and gave the priestess a new order.

”Sister. Do you know how to make holy water?”

”What? Ah, yes. I learned at the seminary, at least... but it’s hard to make it here because of the lack of symbolism...”

”Then go outside and make some now. There’s a prayer room in the annex, so it should be possible there.”

”Yes! I’ll be right back!”

The priestess hurriedly left the room.

After sending the priestess away.

I looked down at my younger sister, whose body was trembling.

Actually, besides the steroid, I had one more card to play.

The problem is that it’s a treatment with absolutely no clinical data.

The thought of using an unverified treatment on my family made it difficult to bring it out.

But... I was out of options now.

’Tsk.’

I was so bold when Fried was born.

To think I’d become so timid after actually coming inside the fence.

’Get a grip, Yulian.’

I’m the protagonist of a Misunderstanding Genre novel.

A protagonist for whom everything works out.

And, a prodigy of black magic acknowledged by the Great Sage.

So there’s no need to hesitate.

’What have I been hesitating for all this time.’

It’s already too late to be having second thoughts.

With resolve, I held Freya’s hand tightly.

I held both of her hands tightly and quietly began to construct the runic formula.

The catalyst is the steroid flowing in her blood.

The convention of the runic formula is a curse.

And, the symbol is...

’...I’m sorry.’

The Y-shaped Cross the priest left behind.

I used that cross as a catalyst.

’Apostle. If you hold the symbolism I think you do...’

Please, sacrifice yourself once more.

I gripped the cross tightly in my hands and whispered as if singing.

”Expurgatio angeli custodis inepti atque fervidi.”

Immediately after the chant ended, magical power drained from my body.

Just as I was worrying it had been a misfire.

The brass cross held in my hand melted,

And soon, Freya’s fever began to rapidly subside.