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I Was Mistaken for a Saint in a Dark Fantasy

Chapter 12: Bastard of a Bloodfiend (1) · Oct 17, 2026

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Chapter List (202)

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1 Chapter 1: I Think I’ve Been Possessed by the Protagonist Who Becomes a Saint 2026-10-17
2 Chapter 2: Is This Possession or Reincarnation (1) 2026-10-17
3 Chapter 3: Is This Possession or Reincarnation (2) 2026-10-17
4 Chapter 4: Angel of the Red-Light District 2026-10-17
5 Chapter 5: You Gotta Oil Up While Living (1) 2026-10-17
6 Chapter 6: You Gotta Oil Up While Living (2) 2026-10-17
7 Chapter 7: You Gotta Oil Up While Living (3) 2026-10-17
8 Chapter 8: You Gotta Oil Up While Living (4) 2026-10-17
9 Chapter 9: Limbus Pit Ecological Report (1) 2026-10-17
10 Chapter 10: Limbus Pit Ecological Report (2) 2026-10-17
11 Chapter 11: Limbus Pit Ecological Report (3) 2026-10-17
12 Chapter 12: Bastard of a Bloodfiend (1) 2026-10-17
13 Chapter 13: Bastard of a Bloodfiend (2) 2026-10-17
14 Chapter 14: Bastard of a Bloodfiend (3) 2026-10-17
15 Chapter 15: Bastard of a Bloodfiend (4) 2026-10-17
16 Chapter 16: Protagonist is always busy 2026-10-17
17 Chapter 17: Protagonist is always busy (2) 2026-10-17
18 Chapter 18: New Skill Tree Unlock? 2026-10-17
19 Chapter 19: New Skill Tree Unlock? (2) 2026-10-17
20 Chapter 20: Limbus Pit’s Winter (1) 2026-10-17
21 Chapter 21: Limbus Pit’s Winter (2) 2026-10-17
22 Chapter 22: Limbus Pit’s Winter (3) 2026-10-17
23 Chapter 23: Limbus Pit’s Winter (4) 2026-10-17
24 Chapter 24: Limbus Pit’s Winter (5) 2026-10-17
25 Chapter 25: Limbus Pit’s Winter (6) 2026-10-17
26 Chapter 26: Flower Blooming in the Plague (1) 2026-10-17
27 Chapter 27: Flower Blooming in the Plague (2) 2026-10-17
28 Chapter 28: Flower Blooming in the Plague (3) 2026-10-17
29 Chapter 29: Flower Blooming in the Plague (4) 2026-10-17
30 Chapter 30: Flower Blooming in the Plague (5) 2026-10-17
31 Chapter 31: Firefly Prince (1) 2026-10-17
32 Chapter 32: Firefly Prince (2) 2026-10-17
33 Chapter 33: Firefly Prince (3) 2026-10-17
34 Chapter 34: Firefly Prince (4) 2026-10-17
35 Chapter 35: Firefly Prince (5) 2026-10-17
36 Chapter 36: Firefly Prince (6) 2026-10-17
37 Chapter 37: Firefly Prince (7) 2026-10-17
38 Chapter 38: Firefly Prince (8) 2026-10-17
39 Chapter 39: Demon Disease (1) 2026-10-17
40 Chapter 40: Demon Disease (2) 2026-10-17
41 Chapter 41: Demon Disease (3) 2026-10-17
42 Chapter 42: Was Mistaken for Daddy-Long-Legs (1) 2026-10-17
43 Chapter 43: Was Mistaken for Daddy-Long-Legs (2) 2026-10-17
44 Chapter 44: Was Mistaken for Daddy-Long-Legs (3) 2026-10-17
45 Chapter 45: Was Mistaken for Daddy-Long-Legs (4) 2026-10-17
46 Chapter 46: Was Mistaken for Daddy-Long-Legs (5) 2026-10-17
47 Chapter 47: Was Mistaken for Daddy-Long-Legs (6) 2026-10-17
48 Chapter 48: Entering High Society (1) 2026-10-17
49 Chapter 49: Entering High Society (2) 2026-10-17
50 Chapter 50: Entering High Society (3) 2026-10-17

The child’s name was Erika.

Eri for short.

This was a fact I learned only after she was forcibly dragged into the consultation room by Wangcho’s rough hands and placated with a few pieces of bread.

”Munch, munch. It’s not candy, but it’s tasty, so I’ll let it slide.”

”So, Teacher. Are you saying this kid isn’t really a Bloodfiend?”

Wangcho asked doubtfully, his arms crossed.

Sitting on the examination table, Eri was still gnawing on the bread with eyes full of suspicion.

”She’s not a Bloodfiend, she’s a patient. The disease is called Paroxysmal Nocturnal Hemoglobinuria (PNH).”

”Is that some kind of magic term?”

”Something like that.”I tried to assemble various ways to explain PNH in my head.

A mutation of the red blood cell membrane makes it vulnerable to the complement system, an autoimmune hemolytic disease...

Hmm.

No matter how I thought about it, I didn’t think he’d understand.

So I just gave him an intuitive metaphor.

”It’s a disease where blood shatters inside the body.”

”Can blood shatter?”

”Just think of it that way. This is also why she has black urine when she wakes up in the morning. The blood escapes through her urine, causing a deficiency.”

I pointed to Eri, who was diligently eating the bread, with my chin... no, my beak.

”Just as an animal instinctively licks rock salt when it’s low on salt, that child instinctively sought out pig’s blood because she was low on blood.”

This symptom is called Pica.

When humans become iron-deficient, they try to put anything in their mouths, usually things like dirt, ice, or uncooked rice.

For this child, that object just happened to be blood.

”Hah... Tsk, tsk. To think I didn’t even know.”

Wangcho clicked his tongue.

The news that the child he thought was a monster was actually a pitiful patient seemed to have pricked what little conscience he had left.

Just then, Eri, who had been mumbling over her bread, asked me a question.

”Mister.”

”Call me Teacher Schnabel.”

”Doc.”

Geez, this kid just can’t get the form of address right.

I sighed and answered.

”Fine. What is it?”

”How did you know the color of my urine?”

Eri’s red eyes stared intently at me.

”Can Healers tell the color of your urine just by touching your stomach and flipping your eyelids?”

Oho.

I was inwardly impressed.

Because she had precisely pointed out the logical leap in my diagnosis process, something even Wangcho had accepted without question.

’She’s smart.’

Diagnosing PNH straight away just from anemia, jaundice, and splenomegaly is close to a logical leap.

It could be cirrhosis, leukemia, or malaria... there are too many possibilities.

”You’re smart.”

I reached out and patted Eri’s tangled hair.

The child flinched and shrank her shoulders but didn’t avoid my touch.

”The truth is, I was just lucky.”

”Aww. That’s disappointing.”

”Deduction is a series of acts, like throwing darts at a target, aiming for the highest score where the answer is most likely to be. In the end, its essence never strays from luck.”

Anemia. Jaundice. And Pica.

These three things alone aren’t enough to completely narrow down the possibilities.

But I had another clue.

”Wangcho told me.”

The one who reacted to my answer wasn’t Erika, but Wangcho.

”I did?”

”You said she ’comes to drink blood every night,’ didn’t you?”

‘Comes to drink blood every night.’

That meant there was a high possibility that the child’s anemia worsened at night.

If I form a hypothesis from there, everything falls into place.

There were no glaring contradictions in this hypothesis. In that case, I just had to go for it.

That’s deduction.

”What do you think?”

Hearing my explanation, Eri’s mouth hung open blankly.

It must seem amazing, since I was reciting it as if I had watched it happen right next to her.

Seeing her reaction, I felt it was worth taking a bit of a gamble with my deduction.

’This is why the patient interview is so important.’

It’s not for nothing that they say it’s important for a doctor to listen carefully to their patient.

Because such a subtle difference in words can sometimes become a crucial clue.

Well, since I was in trauma surgery, I rarely had a chance to listen to patients.

’To be honest, it was luck.’

Actually, if her morning urine color had been normal, I was planning to smoothly move on to a different question.

I probably would have asked if her stomach hurt next.

Thankfully, perhaps thanks to the power of the misunderstanding genre, I was able to get it right on the first question.

”Is your curiosity sated now?”

After my explanation ended, a brief silence fell.

’How about that. Pretty awesome, right?’

Don’t I seem like a genius?

Like Sherlock Holmes, right?

As I was gushing internally, Eri blankly nodded her head.

Wangcho burst out in admiration on her behalf.

”Hah... As expected of you, Teacher. Now that I hear it, it all fits perfectly!”

Wangcho, clapping like a seal with shining eyes.

This is why I like Wangcho.

His reaction is so satisfying.

Right. Clap some more.

I’m the protagonist. I’m Doctor Schnabel.

”Now that we know the cause, is it possible to treat this child?”

At Wangcho’s question, Eri’s head shot up.

In her red eyes, once filled with resignation and disbelief, a glint of something called hope appeared for the first time.

I could also see a flicker of expectation, a belief that a doctor who had unraveled the curse that tormented her would surely have a solution.

Receiving the intense gazes of those two, I answered nonchalantly.

”It’s impossible. It’s an incurable disease.”

”...What?”

The expressions of the two instantly froze.

***

PNH

Paroxysmal Nocturnal Hemoglobinuria

I’m not sure if I remember this correctly because I was in trauma surgery in my previous life, but I recall the injectable drug to treat this disease being incredibly expensive.

Was it Soliris?

I think I remember it being a crazy injectable drug that cost about 500 million won per year.

Even a cheaper one was around 300 million won per year.

I remember it because it was said to be in the lineup of the world’s most expensive treatments.

I think it was said to be more expensive than an anticancer drug.

Of course, I don’t know the ingredients of these treatments, let alone their components.

And there’s no way I could reproduce them in this world.

So I spoke honestly.

”It will probably be difficult to cure the disease right now.”

”...I see.”

The light in Eri’s eyes went out again as she nodded.

The resignation that had filled her red eyes before returned, where hope had just been moments ago.

Just then, Wangcho hurriedly tapped my shoulder with his finger.

”Teacher, your words!”

”?”

”Didn’t you say the same thing about my gout?”

”Did I?”

At my reaction, Wangcho slapped his forehead.

”That habit of yours, blurting out ’it’s an incurable disease’ and only adding ’you just need to take medicine’ much later! That’s a really bad habit!”

...Have I done that?

Come to think of it, I think I have.

I think I was criticized for this by my seniors and the resident doctors in my previous life, too.

— ”Yun-ho! Stop dropping bad news on the guardians out of nowhere! It scares the hell out of them!”

— ”Professor. I believe you’ve omitted the object again.”

Tsk.

Was I wrong?

But from a doctor’s perspective, if it’s an incurable disease, it’s right to say it’s an incurable disease.

Curing and managing are strictly different concepts.

Just like no one in the world says they can cure diabetes, it’s just a disease that needs to be managed.

”I can’t lie to the patient.”

”This is why geniuses are...! Still, there’s an order and arrangement to speaking! If you just blurt out the conclusion, civilians like us can’t keep up with you, Teacher!”

Wangcho lamented.

But I had a lot to say about that part, too.

In school, I was taught not to give patients false hope.

They say that while people don’t file lawsuits out of resignation, many do out of a sense of betrayal.

That’s why I tend to deliver the bad news first, which usually just happens to be the conclusion.

Unaware of my inner thoughts, Wangcho turned away from me and squatted in front of Eri.

”Kiddo. You have to understand. That Teacher is always like that.”

As his large body folded, the Hyena Beastkin’s golden eyes became level with Eri’s red eyes.

”I’m the same as you. I have a disease that won’t heal, but as long as I take medicine, I have no problem living my life.”

Wangcho looked over at me.

”It’s the same for this kiddo, right, Teacher? There is a ’but,’ right?”

It was in the form of a question, but the nuance was closer to ’there had better be a ’but’.’

Under that silent pressure, I set aside the ’180 principles why PNH is incurable’ that I was organizing in my head and gave my conclusion.

”Just as Wangcho said, you’ll probably have to live with this disease for the rest of your life. But I’ll give you back your daily life.”

It can’t be cured, but it can be managed.

In fact, her daily life will be less problematic than gout.

Wangcho, relieved by my firm answer.

The light returned to Eri’s eyes.

In addition, a hint of complaint could be seen.

She looked pouty, as if she thought I had deliberately played with my words.

I could tell without even needing to read her eyes, as her lips were sticking out a mile.

I pushed her lips back in with my finger.

”First, let’s check your blood. The symptoms are typical, but we still need to confirm it.”

I turned and took out some tools from the examination table’s drawer.

Wangcho looked at me, puzzled.

”What else do you need to test?”

”I told you. Deduction ultimately relies on luck. As long as it’s not 100% certain, it’s risky to make a diagnosis based on evidence alone.”

If you suspect a disease, you have to run a test.

The tools I took from the drawer were none other than a glass cup, vinegar, and a syringe.

I held up the syringe and gave Wangcho a look.

Taking the hint, Wangcho grabbed Eri’s arm.

”Stay still.”

Wangcho covered Eri’s eyes.

In that time, I quickly drew her blood.

”Wangcho. Press down hard. This disease already makes hemostasis difficult.”

Wangcho pressed down firmly on Eri’s arm with a cotton ball.

Meanwhile, I divided Eri’s blood into two glass cups.

Then, I dropped a few drops of vinegar into only one of the cups.

The Ham’s Test (Acid Hemolysis Test).

It’s a test that utilizes the fact that PNH red blood cells easily burst when attacked by complement in an acidic environment.

The result appeared immediately.

The blood without vinegar remained red and cloudy.

But the side with vinegar...

”Ooh...! The color...!”

It turned into the color of clear grape juice.

It was such a clear hemolysis (rupturing of red blood cells) reaction that even Wangcho, who was ignorant about medicine, could tell right away.

’Ta-da~ Magical.’

If it weren’t for my persona, I would have joked around like that.

Instead, I patted Eri’s head, telling her she did a good job enduring it.

Eri stared blankly at her own translucent blood.

”What... is this? Magic?”

”Let’s just say it’s more of a magic trick (Trick) than magic (Magic).”

I prepared for the next step.

Now that the diagnosis was complete, it was time for the prescription.

’It can be managed with a blood transfusion.’

Even if PNH can’t be cured, it’s a disease that can be managed to some extent with blood transfusions.

However, before the transfusion, I needed to find the most suitable blood.

I pricked Eri’s finger again to get some blood.

And I took out the blood samples I had stored in advance.

To be precise, they were collected this morning.

Since I had no technology to store blood, it was my habit to collect just enough for the next day from a few people whenever they came for treatment.

”I’ll borrow some of your blood, Wangcho.”

In addition to these samples, I added my blood and Wangcho’s, and mixed them with Eri’s blood.

”Hmm...”

Conclusion.

The result of the cross-matching test: Eri’s blood type matches mine.

”Alright. Let’s do the blood transfusion the day after tomorrow when the blood is ready. Until then, we’ll just manage your nutrition at the clinic.”

”A blood... transfusion?”

Eri tilted her head at the unfamiliar word.

I ignored her and said to Wangcho.

”Take care of Eri for me. Until the transfusion in two days.”

Wangcho nodded.

***

Two days passed, and the promised day arrived.

During that time, a washed red blood cell preparation was completed using 200ml of my blood.

The reason I went to the trouble of processing it into a washed red blood cell preparation is that a PNH patient can have a hemolytic attack if they receive a direct blood transfusion.

However, the journey to make this preparation was a bit complicated.

Draw the blood, have Wangcho’s subordinates tie it to a string and spin it to separate the heavy and light parts, discard the light part, rinse it with salt water, spin it again, rinse it again...

I was able to complete it after working Wangcho’s subordinates hard.

’I knew it, the pyramids really were built by people.’

Sufficient labor can replace technology.

And that labor can be bought somehow with sufficient capital.

Following this formula, as long as you know the principle, even 21st-century pharmaceuticals can be reproduced at a 19th-century civilization level.

’I think it came out well.’

Just in case, I held the washed red blood cells up to the light of the magic stone lamp.

A clear, clean red color.

It passes.

”Alright. Let’s begin.”

I had Eri lie down on the examination table.

Thanks to being fed for two days, a little color had returned to her face.

It’s a natural result after being fed so many iron-rich foods.

Any beast will become docile on a full stomach.

Unlike two days ago, Eri, whose personality had softened, asked a question.

”...Does it hurt?”

”It’ll sting a little. But bear with it.”

I stuck the needle into Eri’s arm.

There were no novice mistakes like fumbling for the blood vessel several times.

I’ve made a living from surgery for so long. I can find a blood vessel in my sleep.

The red liquid slowly flowed into Eri’s blood vessel.

1 minute. 5 minutes. 10 minutes.

”...”

Eri was staring blankly at the ceiling.

”How do you feel?”

”... I’m not sure.”

No problems. Check.

”Tell me if you feel dizzy or short of breath.”

Come to think of it, it’s been a really long time since I’ve done a blood transfusion myself.

After my residency in my previous life, I never had to find a blood vessel myself.

The resident doctors or nurses did all that.

An hour passed like that.

The blood transfusion finished safely.

200ml.

It wasn’t a large amount, but considering this child’s physique, it was enough.

”Rest well today. We’ll check your condition tomorrow and decide whether to give you more.”

Eri nodded.

Eri getting off the bed.

I asked her a question to confirm.

”How is it? Do you still feel the thirst?”

”It’s a little better.”

”Good.”

Correcting Pica is easy, too.

It’s a symptom that disappears quickly once iron and red blood cells are replenished.

In about a week, she probably won’t be looking for blood anymore.

”Let’s get regular blood transfusions like this. You’ll probably have to do this for the rest of your life, but that alone will be enough to live a normal daily life.”

Of course, it’s impossible to make Eri’s disease disappear with blood transfusions alone.

If it were, that several-hundred-million-won injectable drug would never have been developed.

Besides, PNH was a disease that required additional management from a doctor even while receiving transfusions.

However, I didn’t bother bringing that up in such a hopeful atmosphere.

’In any case, managing those risk factors is my job.’

Living a daily life won’t be much of a problem.

Now, she no longer needs to shove her head in a bucket and greedily drink blood.

There’ll be no reason for people to point fingers at her, calling her a Bloodfiend, and she won’t be kicked around by people like Wangcho anymore.

I wonder if that reality hasn’t sunk in for her yet.

Eri fiddled with the adhesive bandage on her forearm.

As if her body, where warm blood had begun to circulate, still felt unfamiliar, the child repeatedly clenched and unclenched her fist.

Then, she lifted her head and met my eyes.

”... Why are you doing all this for me?”

”What are you trying to say?”

”I don’t have any money.”

Eri mumbled in a barely audible voice.

”All I have is these clothes. I... I don’t have the ability to repay what you’ve done for me, Mister... no, Teacher Schnabel.”

The child understood the nature of this back alley better than anyone.

There’s no such thing as goodwill without a price.

Especially in Limbus Pit, kindness without reason usually demanded a more terrible price later on.

A hint of distrust and anxiety could be seen in her.

Usually, what was needed to dispel this was not sincerity.

”Then run errands.”

”What?”

In cases like this, what’s usually needed is give and take.

I pointed a finger at the clinic floor.

”You need to be managed by me regularly anyway. So you’ll work here. I’ll provide you with meals and lodging.”

”...Here?”

”I happened to need an errand runner. Fetching medicine, contacting patients, and occasionally cleaning. Think you can do it?”

”... Okay. I’ll accept.”

The nod of her head was stiff.

It was a nod like stamping a seal on a pledge.

But compared to just a few seconds ago, her wariness had clearly lessened.

’It’s a strange thing.’

Just by turning charity without a price into a transaction, a person’s guard is so easily broken down.

0 Won or the price of a coffee.

Compared to the quality of the treatment, it’s practically the same as free, but just by setting up this negligible hurdle, the reaction changes.

It was like that in Korea, too.

”Wangcho.”

After finishing the deal.

I called for Wangcho, who was waiting outside.

”It seems this child will be the new errand runner starting today. Could you tell her what she needs to do? The same way the other children did.”

”Understood, Teacher.”

Wangcho gave Eri a push on the back.

As Eri crossed the threshold, she glanced back once.

When I gestured with my chin for her to go, Eri turned her head and left.

The two of them left like that, and I was left alone in the treatment room.

I mulled over the recent conversation as I cleaned up the transfusion tools.

— ’All I have is these clothes. I... I don’t have the ability to repay what you’ve done for me, Mister... no, Teacher Schnabel.’

”Well. I don’t think so.”

I muttered a soliloquy that no one would hear.

Erika may only value herself that way, but my thoughts were different.

Now, let’s organize my thoughts.

She has a rare disease.

A rare disease that only I, in the entire world, can diagnose.

To top it off, her blood type even matches mine.

And it’s a disease that requires regular blood transfusions.

Here’s a question.

Would anyone who has read a few web novels really consider this child a normal extra?

No way!

’On top of that, who knows if she’s a polymorphed dragon?’

She could be a future Sword Saint, or a childhood friend who becomes the strongest in the world.

In other words, this is an event.

A buying low event.

’Well, maybe not, but.’

Of course, this isn’t the first child I’ve held onto like this.

A year ago, it was testicular torsion; eight months ago, phenylketonuria; half a year ago, congenital clubfoot; three months ago, congenital diabetes...

Various children have passed through my hands.

Each time, I treated and hired them, searching for their talent.

Among them, there was no SSR or 5-star that I wanted, though.

’Still, this time feels a bit different.’

It’s just... something’s different. It’s hard to explain specifically.

But after saying all this, what if this time is a bust too?

It’d be a shame, that’s all.

They say you perform a rain-making ritual until it rains, after all.

’For now, let’s start with errands.’

Just like the other kids.

If I do that, a talent or two will probably pop up.

I just hope it’s the talent I’m looking for.