The Dimensional Infinity Fortress.

A labyrinth of endless hallways, with doors leading to rooms of varying sizes and capacities. Each having their own unique locations. An ever-shifting palace interior that many would get lost by the sheer scale of this pocket dimension created by one demon.

It was a fortress that can only be entered and exited through the power of that one demon, Nakime, the Biwa Demon. Who, through the use of her Blood Demon Art, created this seemingly endless halls of infinite rooms.

Walking through said halls was the Lord that Nakime served. The Demon King, Kibutsuji Muzan.

On rare occasions had the Demon King that created all demons walked through these walls in his own bemusement. Pondering heavy thoughts weighing on his mind as he recalled recent events that occurred that made him concern for the first time in many years. Or perhaps centuries would be an accurate term to use in this moment.

He had just eliminated all of the Lower Moons, Demons who were constantly and consistently slayed by Hashiras and those who have the capabilities of said Slayers, to end this annoyance that plagued his mind and his patience toward them as favor for them declined each time they died.

This was a move created for the sole purpose of removing them from the equation of having to pick a demon for the slot of Lower Moon every single time one of them died. It was apparent that it was time to finally disband the Lower Moon rankings.

However, he spared only one the remaining Lower Moons, Enmu, who showed promising potential. With it, he decided to give him more blood to prove that the Lower Moons were still useful to his plans.

If he failed and died, that was it. No more giving demons Lower Moon ranks. He was done with them. All he cared more was his Upper Moons, and they were the strongest he could give them credit for with their consistent kills of Hashiras in the past centuries. More so to one of his oldest and most powerful demons in his disposal.

Upper Moon One, Kokushibo.

He has consistently kept his rank throughout the centuries. There were times that his rank was challenged several times, but he proved that he was indeed worthy of that rank. Since then on, he was considered as Muzan's ultimate trump card when he deems the situation to be dire enough to send him on to the battlefield.

Then the thought of losing an Upper Moon demon like Kokushibo suddenly crept through his mind.

It was a scenario that, should the Demon Slayers suddenly gained the strength to overwhelm the Upper Moons and kill them before he could replace with demons qualified for the rank, he would be cornered and left no other choice but to face them with no one to rely on.

That was one of two of his most concerning worst case scenarios. The other being that a new Yoriichi was born in this era.

That was why he began formulating contingency plans to combat such a scenario.

But, no matter how much he thought of there was still a lingering sense of dread looming that those plans might or rendered null in an occasion that the Demon Slayers might have a trump card of their own to call upon that he doesn't know existed.

Continuing his walk through the endless hallways, his mind still burdening the heavy weight of a future where his plans might fail with no alternative options to rely on.

"..."

Closing his eyes, cupping his chin with his right hand; tapping it with his finger as he aimlessly wandered without a care to his surroundings. Knowing that Nakime would simply move the obstacles in this pocket dimension without any hesitation.

Hours passed and no sign of an opportune solution coming out.

Muzan was starting to lose interest in the idea of a contingency plan and was about to abandon it and leave the rest to fate.

Then, he began to realize something he had never considered bringing up again.

For all of his life he had been searching for the Blue Spider Lily throughout Japan. In hopes that he might reverse engineer the medicine created by the doctor who was responsible of turning him into a demon in the first place.

He had searched high and low of the flower. Having pursued the rare plant for centuries and he had no confirmed findings of that accursed flower and no clues to its whereabouts.

Since he could not find it in Japan, then the thought of the flower existing outside abroad in foreign lands is highly probable.

Which makes sense in a logical way.

In 700 A.D. approximately 200 years before Muzan was born, the Red Spider Lily, a plant originally from China, Korea, and Nepal made its way to Japan through Buddhist Monks of China at the time by way of either trade or cultivation of said plant into the country. At the time, Chinese influence on Japanese soil began declining nearly 400 years in the making during the Heian Period (794-1185) where the national culture that would soon mature to what it is known today.

It is possible the doctor must have gained possession of the Blue Spider Lily plant during that time period through that man's connections with the Buddhist Monks.

If that were the case, then it exist within logic and reason. Logically, that's where the plant might came from. And it is reasonable to think that it still exist in its (probable) land of origin.

Before he could rejoice that he finally has a lead on the Blue Spider Lily and before he could berate himself not having thought of it previously, a sudden thought began to form in his head.

If the Blue Spider Lily exists in the West, and the medicine having been created nearly a thousand years ago, were there others who had taken the same drug that turned him into a demon also exist?

That thought made him stop in his tracks. Stopping in the middle of this endless hallway, with Nakime taking note of her Master's sudden pause.

This… this is not possible…

Muzan tried to search in his own memory, the memory of that doctor who gave him the medicine.

He recalled the face of the doctor, the way that he looked back then was as if he was certain that the drug he created would surely heal the previously human Muzan,

At the time, the Demon King thought the doctor's medicine didn't work on him and had decided on killing the doctor before he could finish administering the drug toward him.

It lead him to become a demon that would soon be the Progenitor of All Demons. It was that day his life was changed forever. And he became the Demon King since then.

Now that he recalled his past, he was certain that the doctor knew the effects the Blue Spider Lily was and that man had seen beforehand how it happened.

If… that was the case. Then…

It is possible that there are demons, other than the ones he created himself, exist outside of the country.

Muzan tried to deny such a possibility of demons existing outside of what he created so far, but the more he thought of it, the more likely it was the case.

Which begs the question, who are those demons?

The Demon King had never heard of demons outside the country from his time in the Heian Period to the Modern Era. If they do exist, he would've had heard of their existence by now at least.

In the past, he sent out demons to search for the Blue Spider Lily to help cover more ground in hopes to find it at a faster pace.

Which he, at the time, began realizing the limitations of his power.

The farther he was away from his demons, the less he can sense their presence. And at the time, he was afraid of losing control over his demonic creations. Which he realized that he never sent anyone outside of Japan in the first place to begin with..

So that was the reason why I have never heard of demons outside of this country, huh?

Muzan scoffed at himself and the limitations he now recognized this body has. Cursing that the body he thought was perfect has its own flaws and weaknesses never considered it had other than exposure of sunlight.

Ignoring the recognized flaws and mistakes for now, the next problem should be: Who should he send there?

Having no experience in exploring outside the country, it was obvious he won't let himself be the one to go out there and find the Blue Spider Lily. He already made great connections to various business companies and if he suddenly gone to another country, some would be suspicious of his whereabouts. Even if he made his travels public, there was a possibility the Demon Slayers would follow on where he goes if that brat with the Hanafuda earrings were to somehow sniff out his location. And he knew, despite Nakime's amazing Infinite Dimensional Fortress, its weakness that it still ties in with the country.

He could send the Upper Moons to the West if he wanted, but there are problems with it.

Daki, Gyutaro, and Doma were tied to the Red Light District and a Temple Cult respectively. If they leave suddenly then the people who knew them began to be suspect their sudden disappearances, especially for Daki and Doma. As for Gyutaro, he wouldn't even dare leave his sister behind alone considering she's far weaker than her brother. So those three are out of the equation.

Then, there's Gyokko and Hantengu. Both are excellent choices with abilities that made them superbly difficult to kill. However, they come with their own problems in tow.

For Gyokko, he makes excellent pots and they would sell for expensive prices due to their artistic value which makes most of the money Muzan has. If he leaves and there's no demon to replace those pots once they ran out, it would be bad for business.

Hatengu, on the other hand, relies too much of his clones. If the time came that should his clones were to be destroyed, and the sun conveniently rises when it does so, Hatengu would have no places to hide if he somehow finds himself in a wide, open field.

Which leaves two Upper Moon Demons as his other options.

Akaza can be argued to be qualified for the task. But the man has his code of honor of not harming women. Should he managed to find the Blue Spider Lily and its guardian - if it's possible that flower has a guardian in the first place, which was unlikely but not entirely impossible - who is somehow a woman, he would not be able to harm her because of his code. Which is extremely annoying if it were to happen to say the least.

Which leaves Kokushibo to be the man for the job.

He has centuries of experience fighting Demon Slayers, including the fact that he was also once a Demon Slayer himself. Having him being one of the first Slayers in existence, he should be aware of all the breathing styles that the Demon Slaying Corps have. He is also someone having Breathing Style that Corps did not have, which is a huge advantage in Muzan's opinion.

However, due to these factors, he was considered a trump card that wouldn't order around carelessly. There's a reason why he won't send Kokushibo out to battle without a solid reason to do so..

This left Muzan in a dilemma.

If he can't go and his Upper Moons either, then there's no hope of getting that Blue Spider Lily in the Western world.

Even if he does let them go toward west, there's no telling that there might actually be demons roaming around under someone's blood and control. And they might be stronger than the Upper Moons themselves, perhaps even stronger than himself, Muzan.

This was a problem Muzan knew he could not have the capability to answer to.

Which left two options.

One, should a demon who could adapt to the sun appear and devour them so that the pursuit of the Blue Spider Lily can no longer be deemed a necessary. And destroy the Demon Slaying Corps once and for all.

Or, let his dream of gaining a perfect demon body die and let another demon take his place as Demon King. Which would let the Demon Slayer Corps kill him once and for all, and the chosen successor would go on with their journey toward West to find the origin of the Blue Spider Lily.

Seconds passed, and Muzan knew exactly what to choose from.

But he needed time to prepare.

Months went by in a flash, the deaths of Upper Moons 6, 5, and 4, as well as the discovery that a demon has finally adapted to the sun now has shown herself, Muzan needed to act immediately. Otherwise his plan would fail if things kept up at this rate.

He was hesitant at first, he knew the plan was extremely risky to begin with, but with the deaths of half of his Upper Moons, he didn't have any choice left either.

"Kokushibo!"

Muzan's voice boomed, the sound echoing throughout the Infinity Castle. It commanded great authority.

"I am here… My Lord."

The voice of a noble man, with elegance in his tone who commanded a great deal of power worthy to be the strongest of the demons under the Demon King's control.

Kneeling in front of the Demon King is the Upper Moon One demon, Kokushibo.

Satisfied with Kokushibo's arrival, Muzan began saying:

"For centuries, you have been my most powerful and loyal demon, Kokushibo. You, who have hold the rank of Number 1 for three hundred years since you became a demon, and have enhanced your fighting style since then. Back when I promised you longevity and power to surpass your brother."

Mentioning his late brother made Kokushibo visibly flinch, but it did nothing to deter Muzan from continuing.

"It would be extremely rude of me to not give you any more of my power. For with the recent deaths of two Upper Moons in a single night, the Demon Slayers morale are at an all-time high. And entrust you of a plan of mine once I give you more of my blood."

Kokushibo rose his head, his six eyes stared at his Master in disbelief. It's as if he had seen a ghost himself.

Muzan knew that it took Kokushibo three whole days to become a demon years ago, but the blood he gave to him was far larger than any demon he gave throughout his near thousand year life on this earth.

He deliberately chose Kokushibo as his successor because he fits the role of Demon King well. With his swordsmanship and Breathing Techniques in hand, he will be an unstoppable force of nature. Something he hoped would've dealt the Demon Slayers, but he doubt that happen due to their likelihood of possessing a trump card.

But making Kokushibo a direct successor would cause turmoil with his remaining demons a nuisance. This successorship was done in absolute secrecy.

In fact, he never told Kokushibo that he would his successor in the first place.

"I am deeply honored, My Lord."

Breaking out of his thoughts, Kokushibo proud but faint voice brought Muzan back to reality. Then the Demon King proceeded with the next phase of his plan.

"I see you did not object. Good. Now, here's the plan. I will attack the Headquarters, the very heart of the Demon Slayer Corps, where all the Hashiras are located. And I will… give someone a visit while I'm over there."

A faint hesitation escaped Muzan's lips at the end. Kokushibo caught that on, but remained silent as Muzan continued on.

"You will have then until I lure the Demon Slayers into the Infinite Dimensional Fortress where you enhance your skills to its utmost ability. I would suggest you will give it your all since a certain boy has someone in your past resonate inside of him…"

After saying those words, Kokushibo froze. A myriad of emotions began welling up inside of him with the primary ones being hatred and a faint of sadness. Muzan knew exactly what those emotions are aiming for.

The Demon King he couldn't directly order Kokushibo to run away with most of the blood given to him, he knew that his Upper Moon One would see it an act of cowardice and it would go against his pride as a warrior.

Which was why this part of the plan has to be relied on to Nakime.

Should the Infinity Castle collapse after her death, he made sure to brief her of the plan to sent Kokushibo on the outskirts of Karafuto Prefecture, the farthest location she can send someone to, and he would give Upper Moon One his final order once the first signs of the pocket dimension's collapse was shown. Which would separate him and the Demon Slayers once it happens.

With no time to waste, Muzan immediately gave his blood to Kokushibo. With it, the largest amount of blood he had ever gave to someone.

The effects of receiving the blood was clearly shown before him.

He can see Kokushibo's eyes boiling in pain and anger wiith such intensity, Muzan could've mistakenly thought that hate was directed at him.

It was the longest minute Kokushibo had in his life had, but soon after that, the pain dissipated, and he had received an unprecedented amount of blood from the Demon King himself, which also gave him a good boost in power.

"Kokushibo… listen carefully. You must know, that with this amount of power and blood I gave you, you will be the new Demon King…"

Muzan said toward the awe struck Kokushibo, who looked at his hands opening and closing to feel any difference of power before the Demon King continued.

"I cannot stress of how much you can reach with the power you have now, and it will grow once you have gotten accustomed to it and improve from it… I cannot reach your strength any time soon. You must not let me down, Kokushibo."

With awe and wonder in his voice, Muzan can see the potential that Kokushibo has with the amount of blood he gave. He hoped it would be enough to accomplish his plans.

Upper Moon One only nodded as he rose to his feet.

Muzan could faintly hear his strongest demon mumbling to himself on how he would take his revenge on this certain individual from his past.

The only known living user of his brother's technique, the legendary Sun Breathing.

"Doma… Akaza…"

A whispered utterance of the names of the remaining Upper Moons, who were now slain by the Demon Slayers once their presence were no longer felt.

"I had faith that the two of you would end them… faith that you two would succeed. Yet, you threw your lives away… what a disappointment."

The former Upper Moon One, now a successor to the Demon King, was furious at the state the situation has become.

But he decided to stay level-headed and stand within the shadows.

Once the Demon Slayers drop their guard after thinking they have killed the King of Demon, Muzan. He would swoop in and kill the remaining Demon Slayers at their weakened state.

He hoped that his Master would take them out with himself as a show that even though he was weakened by the drug created specifically for the Demon King, it would enough to take down some of them. With the rest he could handle alone.

What Kokushibo and the Hashira didn't know at this moment, it was all part of Muzan's plans.

They were all pawns in Muzan's grandiose plan. And the Demon King hoped it would work into his favor.

That's it. Just a little bit more."

Muzan never thought that in his entire life where he had hoped that his own death would worth it in the end.

He was at the end of the line, and he knew that better than anyone would.

Come on, come on. Please work.

After dodging an incoming flail by sheer skin of his teeth, which tore off piece of his flesh.

By now the Demon Slayers had awakened the use of Transparent World, their Demon Slayer Marks, the burning red Nichirin blades. Muzan can easily see that they are giving it their all.

All of the Hashiras are present, the brat with the Sun Breathing is here, the rest of the Demon Slayers are all here.

He could feel it. His death is imminent.

Bullets began to pierce his skin, a tree sprouted to entangle and ensnare him.

Every single human began unleashing attack after attack in quick succession as if their very lives are at stake.

This was it.

With parts of his flesh cut off and no longer regenerating his head fell of his body, he knew his battle with them is finally over.

Never had he felt death so rewarding.

Muzan cackled maniacally instead of screaming curses at the Demon Slayers. However, he was ecstatic that everything has been coming together as part of his plan.

"You Demon Slayers are not even close to my level! I was weakened! I was poisoned! But that shouldn't be your main concern, humans!"

He continued his maniacal laughter, greatly unnerving all the Slayers gathered together. Feeling a sense of dread they could not comprehend.

"I am no longer the Demon King anymore! In other words, all of you are dead to me and you'll all be sent to hell for all I care!"

His remaining flesh began to disintegrate, turning to ashes in the wind. But he gave his final words to his subordinate one last time.

"DO IT NOW, NAKIMEEE!"

With that, the Infinite Dimensional Fortress began to crumble before their very eyes.

With that, the walls of the Infinite Dimensional Fortress, which held the lair Kibutsuji Muzan, a safe haven for the Demon King, was now falling.

With it, Kokushibo and the rest of the Demon Slayers, Nakime using every last amount power he had; sent them away. Far from each other.

It all seemed to work well, with Muzan's careful planning with his death as his final piece of his plan. He had succeeded where his contemporaries have failed.

However, there was a huge miscalculation to his plan.

Kibutsuji Muzan, for all intents and purposes, had severely underestimated Nakime's ability to open the doors of her Infinity Castle.

She could open doors in any place, regardless of time and space continuum. She had experimented the limits of her Blood Demon Art without Muzan noticing her every time.

Nakime attempted to open doors that lead to locations outside of Japan. Some for her personal amusement which she kept hidden from her Master's eyes in secrecy. Some objects can be labeled as simple pieces of literature from foreign cultures.

Another grave miscalculation Muzan made that he underestimated Nakime's will to live.

She did not want to die, but wasn't given orders to die, only to destroy the Infinite Dimensional Fortress. That's what matters.

The Biwa Demon can rebuild the Infinity Castle, after all, she created the fortress to begin with.

Now that she no longer bound by her former Master's command. She can send the intruders and her master's successor to a place only she can freely travel to on her own.

Only that when the story of the fate of these individuals be told through her eyes.

AND CUT!

PHEW! THAT WAS INTENSE, HOPEFULLY MY WRITING SKILLS ARE STILL WORKING… I HOPE SO.

ANYWAYS, IF YOU GUYS WANT TO KNOW WHERE OUR FAVORITE CHARACTERS ARE GOING, BE SURE TO CLICK THE CHOICES IN THE POLL THAT I MADE WHICH WOULD DECIDE WHERE OUR FAVORITE KNY CHARACTERS GO TO.

I WON'T SAY WHERE, BUT IT'S WHERE THE POLL DECIDES.

THAT'S ALL FOR NOW. gabrielchiong11 out