Super God: The Foundation, Starting by Inventing SCP

A Net of Heaven member in a black bodysuit told Black-and-White Xuan Jian, "No one can keep secrets from the Net of Heaven!"

"Give me two hours, and I'll make him tell us everything we want to know!"

Black-and-White Xuan Jian, holding his twin black-and-white blades, nodded. Then he looked up at the slowly rising sun. What lay behind those eyes, neither joyful nor sorrowful...

Who knew what he was thinking?

Dozens of Demon Slayer Corps members lay dead around them!

Like CP0, the Net of Heaven had not started a livestream, following Zhao Gao's orders. They had chosen to send word back to their world through private messages instead!

Elsewhere, a group of ninjas with cracks across their faces and several thousand White Zetsu appeared deep in the mountains.

Hundreds of thousands of fugitives from various worlds had also arrived in the Demon Slayer World.

And these were only the advance forces.

Countless more opportunists were on their way, hoping to turn their fortunes around by exploring the Demon Slayer World.

At that moment, the entire Demon Slayer World descended into chaos!

Aside from a few organized groups, these opportunists all started livestreams to show the myriad worlds their journeys through the Demon Slayer World.

Of course, the livestream with the largest audience...

Was still the SCP Foundation's. Neither its viewer count nor its quality was in the same league as the other streams.

Every viewer in the SCP Foundation's livestream was watching SCP-049, the Plague Doctor, intently. Would he attack Tanjiro and Nezuko?

What happened next left them baffled.

They had imagined that SCP-049 would kill Tanjiro and Nezuko outright, then turn them into zombies.

Instead, SCP-049 began examining Nezuko's injuries like an ordinary doctor.

As he worked, he asked Tanjiro, "Young man, how was your sister hurt?"

"Judging by the wounds, it wasn't a wild animal!"

"It looks more like a person bit her!"

Tanjiro watched SCP-049 examine Nezuko's wounds with practiced hands. He also could not smell any hostility from the strangely dressed figure.

Most of his wariness gradually faded.

When SCP-049 asked him what had happened, he answered at once, "I don't know!"

"I went into town to sell charcoal yesterday. The heavy snow blocked the mountain paths, so I spent the night by a big tree at the foot of the mountain. When I got home, I saw..."

"My mother and the others lying in pools of blood!"

"My sister was the only one still breathing."

"So I carried her toward town, and then I ran into you!"

Tanjiro took a deep breath and asked shakily, "Doctor, can you save my sister?"

"She's the only family I have left."

"I..."

SCP-049 listened while examining Nezuko. "Don't worry," he said calmly. "With me here, there's no patient I can't save."

"Especially one so..."

Joy surged through Tanjiro. "Doctor, if you save Nezuko—"

"No matter how much it costs—"

"I'll..."

But before Tanjiro could finish, he caught the scent of intense hostility in the air. It was so strong, so cold...

Fear stopped his words and left him standing frozen in place.

He could barely breathe.

More terrifying still, that murderous intent came from the bird-beaked doctor who had been gently asking about Nezuko's injuries just moments ago.

Tanjiro could not understand why the doctor had suddenly turned such fierce hostility on him and Nezuko.

He had done nothing to offend him!

Tanjiro did not know that the livestream's viewers, too, were gripped by inexplicable terror.

The dread that rose from the depths of their souls reminded them of the fear SCP-173, Little Peanut, and SCP-096, Shy Guy, had inspired!

Under Tanjiro's bewildered gaze, SCP-049 stared at Nezuko and roared, "The pestilence! You carry the pestilence!"

"Heh..."

"You hid it well! I nearly missed it! Every trace of the pestilence must be treated!"

"It must... be treated!"

SCP-049 reached his slightly withered fingers toward Nezuko, who had lost consciousness from her injuries.

He intended to take her life on a conceptual level to treat the pestilence.

Just then, a dazzling blade flashed. Giyu Tomioka, the Water Hashira, appeared in his Demon Slayer Corps uniform and saved Nezuko...

At the same time, he used his Water Breathing to free Tanjiro from his fear and restore control of his body!

To Treat the Pestilence: Conceptually Erasing Giyu Tomioka, Tanjiro, and the Souls of Sabito and the Others! SCP-049 looked at Giyu Tomioka, who stood in his way, and spoke in an impossibly hoarse voice. "You carry the pestilence too!"

"All of you do!"

"You nearly escaped my notice! You must be treated!"

Tanjiro, able to move again, shouted at SCP-049, "We don't have the pestilence!"

"My sister is just hurt!"

"It isn't the pestilence!"

As he spoke, Tanjiro tried to take Nezuko from Giyu Tomioka and bring her to the town at the foot of the mountain for treatment.

He knew the delay had cost them precious time.

Nezuko might already be beyond saving.

But he would not give up as long as there was even the slightest hope. Nezuko was the last family he had in the world.

To his shock, the swordsman who had appeared out of nowhere stopped him.

That was not what mattered most, though.

Nezuko, whose breathing had nearly stopped, suddenly began struggling violently. Tanjiro was overjoyed at the sight.

But before he could speak, he saw that fangs had grown in Nezuko's mouth.

Her once-clear eyes had turned bloodred.

She let out an unintelligible growl. If Giyu Tomioka had not been holding her back, she looked ready to devour Tanjiro alive.

The sight brought back the legend the old man at the foot of the mountain had told Tanjiro the night before!

Nezuko had become a demon!

No!

Nezuko could not have become a demon!

While restraining the transformed Nezuko, Giyu Tomioka asked SCP-049, "Did you see that she was about to turn into a demon?"

"Is that what you mean by 'the pestilence'?"

Giyu Tomioka studied SCP-049. His clothes were strange, and he filled Giyu with a dread unlike anything he had felt before.

But he definitely was not a demon!

So Giyu Tomioka instinctively assumed that the strangely dressed figure meant demon transformation when he spoke of the pestilence!

"Demon transformation? No! That isn't the pestilence!"

Though furious, SCP-049 still explained, "The pestilence is catastrophe! Mass extinction..."

"Oh, how can I explain it to you?"

SCP-049 seemed unable to find the right words. He struck his own temple and said, "But I know I must find a way to cure the pestilence completely!"

"Many have chosen to yield, but I never will! Ridding the world of the pestilence is my duty. I will find a treatment that ends it all."

"Before that, of course, I must eliminate every carrier!"

"And you are carriers of the pestilence!"

SCP-049 stepped toward Giyu Tomioka. He seemed to move slowly, yet in an instant he was standing before him.

Then he pointed a withered finger at Giyu Tomioka.

Giyu Tomioka was the Water Hashira!

He had fought countless battles. The instant SCP-049 moved, Giyu felt an immense pressure.

More than a decade of combat experience warned him.

His opponent was not a demon, but he was more terrifying than one. If Giyu held anything back, he would die here.

Without hesitation, Giyu Tomioka unleashed his Water Breathing, hoping to kill SCP-049 in a single strike!

"Water Breathing, Eleventh Form: Dead Calm!"

At Giyu Tomioka's call, a pale-blue domain appeared around him. Everything within it fell still.

Streams of water formed blade after blade and slashed at SCP-049's withered body as he approached.

Water Breathing, Eleventh Form: Dead Calm was a technique Giyu Tomioka had created himself.

It let him enter a state of perfect stillness.

Within its domain, it could also nullify any technique. It was Giyu Tomioka's strongest killing move.

He was certain it would wound SCP-049, even if the doctor was as powerful as an Upper Rank demon.

But what happened next stunned Giyu Tomioka.

The water blades, strong enough to wound an Upper Rank demon, struck SCP-049. They did not kill him. They did not even tear his clothes.

They certainly did not slow his advance.

Soon it would be too late.

Giyu Tomioka realized the gulf between them was too great. His only chance of survival was to run.

But before he could flee...

A finger entered his field of vision. It grew larger and larger, then came to rest between his brows.

Giyu Tomioka's vision went black. He sank into eternal darkness.

After killing Giyu Tomioka, SCP-049 immediately reached toward the stunned Tanjiro and the demon-turned Nezuko.

Tanjiro wanted to dodge, but even Giyu Tomioka had failed to evade that attack.

What chance did Tanjiro have?

He could only watch as SCP-049's withered finger touched his forehead. Then both Tanjiro and the transformed Nezuko...

Fell completely still!

Just as the livestream's viewers thought it was over, two translucent souls rose from the bodies of Giyu Tomioka and Tanjiro...