This was a somewhat grey and backward town compared to the rest of the continent.
Even so, the night was always a time of indulgence.
After an exhausting day of work, people whose bodies and minds were worn down always wanted to relax when they finally had the chance.
And that was no different for this dull, grey town.
Neon lights flickered across the streets.
People laughed and chatted as they wandered through the lively night market.
But in a remote alley—
There stood a young man who clearly did not belong here.
Yes.
He was very young.
A teenager wearing worn-out grey cloth clothing.
His bright crimson eyes resembled two dazzling yet eerie red gemstones.
His body was thin and gaunt, and his skin was pale in a sickly way, as if he had not seen sunlight for a long time.
Excitement twisted his expression.
No matter how one looked at him, he did not seem like a normal person.
"It's real… I'm finally normal!"
The sickly young man, Mammon, stared at his hands with crimson eyes.
Feeling the strength when he clenched his fists, he was so excited that he could barely control himself.
He truly…
Had become normal.
Heaven knew how many times during these sixteen years he had wanted to kill himself.
Because he had never been a normal person.
Not in any other sense—
But physically.
He had been born with an extremely weak constitution.
When he was born, death had already wrapped tightly around him.
His heart had even stopped beating once shortly after birth.
But Mammon had survived through his desperate desire to live.
Through sheer stubbornness, he crawled back from the gates of death.
Even so, his body remained extremely weak.
After the age of ten, even something ordinary people took for granted—walking normally—became extremely difficult for him.
He could only rely on a wheelchair to move.
But now—
He was finally normal.
When he clenched his fist, he could feel the strength clearly.
Yet just a few minutes ago, he could not even properly close his fingers.
"That system… it's real!"
"My body really recovered!"
Feeling the power flowing through his body, Mammon's lips stretched into an exaggerated smile.
Just moments ago—
The instant his sixteenth birthday arrived, a system suddenly appeared in his mind.
And it unlocked a character template.
The final boss of Demon Slayer—
Kibutsuji Muzan.
The infamous "scumbag boss."
Mammon still remembered Muzan very clearly because he carried memories from his previous life.
That guy was famous for being cowardly and extremely evil.
Countless fans had joked about wanting Muzan to:
stand under the sun
drink wisteria tea
undergo painful scraping therapy
and all sorts of punishments.
But none of that mattered.
No matter how people felt about Muzan, Mammon was thrilled that he had obtained all of Muzan's abilities.
A healthy body.
This was something he had dreamed about his entire life.
Anyone who had never experienced true weakness would never understand the despair—
the feeling of being swallowed by an abyss of hopelessness.
"Hahahahahaha!"
Mammon clenched his fists tightly and laughed wildly.
Yet tears unknowingly flowed from the corners of his eyes.
Health.
Strength.
Sixteen years of darkness and repression had finally shattered today.
"Blood Curse… Blood Demon Art…"
After venting his emotions for a while, Mammon wiped away his tears and began to examine his new body.
What he had obtained was the template of Muzan at his peak.
And with it—
All of Muzan's power.
The most terrifying of these abilities was undoubtedly the Blood Curse.
It could be said that this power was the source of all tragedies throughout the entire story of Demon Slayer.
That tragedy was—
Demons.
The demons in Demon Slayer are not the same as the usual concept of ghosts.
They feed on human flesh, possess immortality, and powerful demons even gain supernatural abilities known as Blood Demon Arts.
And the origin of all demons—
Was the Progenitor Demon, Kibutsuji Muzan.
Through the Blood Curse, Muzan can transform humans into demons.
By giving them his blood, the curse takes effect and the transformation begins.
The strength of a newly created demon depends on how much blood Muzan grants them.
Of course, demons can also grow stronger later by devouring humans.
However, their innate talent determines their limit.
Once they reach that limit, no matter how much they eat, they cannot grow any stronger.
"If that's the case…"
"Then I finally have the qualifications to pursue power and authority."
A cold smile appeared on Mammon's lips.
As if recalling something unpleasant, a chilling glint flashed through his crimson eyes.
Sixteen years of being crippled had already twisted his mind somewhat.
Living in constant despair day after day—
The only reason his sanity had not collapsed completely was because he retained the maturity of twenty years of memories from his previous life.
Even so, his mind was no longer the same as that of ordinary people.
And besides—
This world itself was far from normal.
At that moment, three staggering figures walked into the alley from the other end.
They carried liquor bottles and cursed loudly as they walked.
Clearly, they were drunken hooligans.
Bang!
One of them failed to notice the thin young man standing there.
His shoulder slammed directly into Mammon.
But it felt like he had collided with a wall of iron.
The recoil knocked him backward and he fell to the ground.
"Damn it! You brat, don't you watch where you're going?!"
The blond drunk rubbed the place where he had fallen.
The shock sobered him up quite a bit.
Without even looking carefully, he angrily shouted at Mammon.
"Sorry."
"But I haven't moved from this spot."
Mammon's expression didn't change.
He only glanced at the blond man calmly.
He had seen many unreasonable thugs like this before.
"What did you say?"
"Forget it, Red. Why bother arguing with a half-dead guy like this? Bad luck."
The blond man was about to teach the frail boy a lesson.
But the red-haired man beside him interrupted impatiently.
When Mammon heard those words, the crimson in his eyes darkened instantly.
"Yeah, look at his face. He probably won't live long anyway."
The blond man circled Mammon and looked him up and down.
A mocking smile spread across his face.
With that sickly pale complexion, he looked like someone who had been ill for years.
"…Do I look half-dead?"
Mammon lowered his head slightly and asked in a low voice devoid of emotion.
His crimson pupils had already transformed into vertical beast-like slits, ferocious and terrifying.
"Hah? Don't you look half dead? Look at your face—like a corpse—"
The blond man sneered mockingly.
But before he could finish—
He would never get the chance.
Mammon raised his left hand.
In an instant, his palm twisted grotesquely into a massive lump of flesh.
A huge mouth filled with fangs opened and bit into the blond man, lifting him into the air.
"AAAAAH!"
The blond man screamed in agony.
The fangs had already pierced deep into his body.
Bright red blood dripped continuously.
The red-haired man and his companion were frozen in terror.
CRACK!
A horrifying crunch echoed through the alley.
Half of the blond man's body fell limply to the ground.
Blood poured down like rain.