Super God: The Foundation, Starting by Fabricating SCPs

"We discovered that a species called 'Demon' exists in the Demon Slayer World!"

"They feed on humans. They're an extremely evil species."

Doctor Kuroto paused, then continued, "Of course, according to Doctor Carl's observations, demons aren't particularly strong."

"Even the progenitor of demons, Muzan Kibutsuji, is only comparable to a first-generation divine body."

"And they have a fatal weakness: sunlight!"

"Expose them to sunlight, and even Muzan Kibutsuji will turn to ash."

Everyone in the livestream was stunned by Doctor Kuroto's words. They had expected the Demon Slayer World to be dangerous.

But its strongest fighter was only on the level of a first-generation divine body.

And demons had such a glaring weakness.

With strength like that, civilizations at the pinnacle of the Super God Universe—the Angel Civilization, the Underworld Civilization, and the Demon Civilization—would have no trouble wiping them out. Even the various Indigenous Worlds...

...were confident they could exterminate the Demons.

Of course, they all knew that if the Myriad Races Livestream and the SCP Foundation took the Demon Slayer World so seriously,

it couldn't be as simple as it appeared.

Some unknown danger had to be lurking beneath the surface.

As the powerful figures from various worlds in the livestream frowned and pondered what the Demon Slayer World's true danger might be, Doctor Kuroto spoke at just the right moment:

"While Doctor Carl was using containment object SCP- to observe the Demon Slayer World,

"she was startled to discover that this low-level world possesses the concept of reincarnation.

"That put Doctor Carl on alert.

"Ordinarily, low-level worlds have no concept of reincarnation unless it formed when the world was born, as it did in Aizen's Soul Society World and Hiruzen Sarutobi's Ninja World!

"But even when reincarnation exists, it remains incomplete!"

Doctor Kuroto paused, then continued, "The Demon Slayer World's reincarnation system, however, is remarkably complete.

"If the Demon Slayer World ever fully connects with the Super God Universe,

"the Super God Universe will most likely acquire the concept of reincarnation under its influence.

"According to Doctor Carl's prediction, this is likely the result of an unknown containment object. And the emergence of demons as a species

"is suspected to be caused by SCP-610. Strangely, though, their symptoms are completely different from those in our records!

"So we still can't determine the cause of the Demon Slayer World's mutation. Doctor Carl's conclusion is that SCP-610, The Flesh That Hates, and an unknown containment object are suspected of acting together to cause it!

"And if even a single particle enters the Super God Universe,

"the Super God Universe will be contaminated.

"Therefore, after review and approval, the Foundation has decided that anyone who enters the Demon Slayer World is forbidden from returning to the Super God Universe without authorization.

"Otherwise, the SCP Foundation reserves the right to use any means necessary to erase them on a conceptual level!"

Everyone in the livestream froze at Doctor Kuroto's words. They had braced themselves, but they had never imagined it would be this serious!

Two Containment Objects acting together had caused the mutation.

More importantly, even the SCP Foundation had no information on one of the Containment Objects.

Add SCP-049, the Plague Doctor, and the tiny Demon Slayer World contained three Containment Objects. The danger was obvious.

That warning was enough to deter most of those who had planned to explore the Demon Slayer World.

Of course, some people simply refused to heed warnings.

A few stubborn souls still intended to investigate. They firmly believed the SCP Foundation had said all this to keep the benefits of exploring the Demon Slayer World for itself!

[Monkey D. Dragon: I've ordered every member of the Revolutionary Army to stay out of the Demon Slayer World! But those Celestial Dragon scum will definitely ignore the warning!]

[Sengoku: The three admirals and I submitted a request to the Five Elders, but we haven't received a response yet!]

[Whitebeard: Sengoku, you already know the answer, don't you?]

[Tatsumaki: @Monster King Orochi, keep your monsters under control. Otherwise, our world could be destroyed because of this.]

[Monster King Orochi: Too late. Meow-Meow has already led an army of monsters into the Demon Slayer World!]

[Blast: @Monster King Orochi, you really deserve to die!]

[Hiruzen Sarutobi: The Five Great Ninja Villages have agreed that none of us will enter the Demon Slayer World. @Pain, keep your Akatsuki in line!]

[Pain: The Akatsuki won't enter either. As for other ninja, I can't say.]

[Ying Zheng: Six Kingdoms Remnants, heed my warning: don't play with fire unless you're ready to get burned!]

[Zhang Liang: @Ying Zheng, First Emperor, you'd better keep the Net of Heaven in line too!]

[...]

Just then, Doctor Kuroto's voice rang out again. "According to the latest news from Doctor Carl, SCP-049, the Plague Doctor, has indeed entered the Demon Slayer World!"

"Now, watch the livestream to better understand the dangers of the Demon Slayer World."

With that, Doctor Kuroto's slightly gaunt figure faded from the livestream, replaced by a snow-covered mountain.

A line of small text appeared in the upper-right corner: [Demon Slayer World · Mount Kumotori].

Then the view shifted!

A red-haired, red-eyed boy in a green checkered haori was sprinting toward the town at the foot of the mountain with a girl on his back.

Standing directly in his path was SCP-049, the Plague Doctor, clad in a black robe and wearing a crow mask.

At the sight of SCP-049, the viewers' pupils contracted.

The SCP Foundation really is reliable, they thought.

It had said SCP-049 had gone to the Demon Slayer World, and there he was. At the same time, everyone began to wonder

whether SCP-049, like SCP-096, Shy Guy, before him,

had been deliberately sent into the Demon Slayer World by the SCP Foundation.

The Foundation could investigate the world's secrets and run an interaction experiment at the same time.

The more the viewers thought about it, the more likely it seemed. Given what they knew of the SCP Foundation's methods,

it was exactly the sort of thing the Foundation would do.

Just then, the red-haired boy carrying the girl reached SCP-049. Seeing that SCP-049 made no move to get out of the way,

he shouted anxiously, "Move!"

"I need to find a doctor in town!"

"Get out of my way!"

At the boy's words, SCP-049, the Plague Doctor, suddenly looked up at him and said in a raspy voice, "Boy, you're looking for a doctor?"

"What a coincidence."

"I am a doctor. May I examine the girl's injuries?"

The red-haired boy froze at SCP-049's words, then stopped and eyed the strangely dressed figure with suspicion.

Is he really a doctor?

He had lived on Mount Kumotori for over a decade. He had never seen this person before, or even heard of him.

Strangely, though, he detected no hostility from him.

Under normal circumstances, Tanjiro might have refused. But Nezuko's breathing was growing weaker, so faint he could barely detect it.

At this rate,

she would never make it to town. After weighing his options, Tanjiro decided he had nothing left to lose and accepted SCP-049 the Plague Doctor's offer.

He let him treat his younger sister, Nezuko.

The person before him might be dressed strangely, but he bore Tanjiro no ill will.

What if he can save Nezuko?

At the sight, countless viewers in the livestream felt their pupils contract sharply!

SCP-049, the Plague Doctor: Nezuko Is Infected with the Plague. She Must Be Treated!

Meanwhile!

On a bustling street in Tokyo, in the Demon Slayer World,

a Void Passage appeared out of nowhere. A Cat Person strode out with a group of monsters as the surrounding crowd stared in disbelief!

After a brief stunned silence, the crowd erupted into chaos!

"Monsters!"

"Run! They're monsters!"

"Help! Monsters! Run!"

"..."

Meow-Meow watched the crowd scatter. He ran his blood-red tongue over claws that glinted in the morning sun, then gave a cruel smile.

"No annoying Hero Association!"

"Finally, we can kill without holding back!"

"Kill!"

"Let blood and screams announce the Monster Association's arrival in the Demon Slayer World!"

As he spoke, Nyan flicked his claws. People within a few hundred meters were sliced into chunks of flesh. He speared a heart on one claw

and popped it into his mouth, chewing with a look of rapture. "Delicious. You should all have a taste!"

At Nyan's command, hundreds of monsters surged off in every direction.

They began slaughtering everyone in sight!

In moments, all of Tokyo became a battlefield, filled with screams, explosions, and the monsters' excited roars!

Seeing this in the livestream, Tatsumaki posted at once: [@Monster King Orochi, you really deserve to die! Wash your neck and wait for the end!]

[This time, the Hero Association won't let you off!]

[Let's go to war!]

[And we won't stop until one side is dead!]

Monster King Orochi fired back: [Natural selection. Survival of the fittest. That's the way of the world! We monsters were born of the world's will.]

[Compared to humans, we're a superior species.]

[If you want war, then war it is!]

Seeing their messages, Whitebeard couldn't resist posting: [@Tatsumaki, if the battle goes badly, the Whitebeard Pirates can back up the Hero Association!]

Tatsumaki: [@Whitebeard, no need, old man. The Hero Association can handle one measly Monster King Orochi!]

Monster King Orochi: [Big words!]

Mount Natagumo, in the Demon Slayer World!

A group of Cipher Pol Aigis Zero agents in white suits crossed through a Void Passage, led by Rob Lucci. After arriving on Mount Natagumo, they used Observation Haki...

...to locate the lair of Rui, Lower Rank Five.

Then they used Soru, launched themselves into the air, and headed straight for the lair!

Under orders from the Celestial Dragons, they had not started a livestream. Instead, they sent everything they learned about the Demon Slayer World to the Five Elders through private messages.

At a Demon Slayer Corps Outpost in the Demon Slayer World!

"Captain, leave it to me!"