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Kokushibo did not expect to be summoned back to headquarters so soon. It had only been - what - three months at most since the deaths of Gyutaro and Daki. This meant that another Upper Moon was defeated.
Kokushibo quickly glanced around the disorienting, spiraling maze of the fortress. There was Akaza, looking a lot more openly confused. And Doma, with his usual cheeky grin.
No Hantengu or Gyokko. Ah, so they must have been killed on that mission that man sent them on.
“W-what’s going on?”
There was a demon right by his side. Kaigaku, if he remembered correctly. The Breath of Thunder user he recently converted.
“It would be… wise… for you to… know your place,” Kokushibo told him. “The master… will arrive… soon enough…”
Kaigaku looked terrified, but kept his mouth shut. At least he respected the chain of command, clearly recognizing he was inferior among them.
“Kokushibo-dono!” Doma cheered. From their perspective, Upper Moon Two was upside down, leaning over a staircase railing. “It looks like Hantengu and Gyokko are dead! Such a shame! Who’s your new friend?”
“Shut it,” Akaza muttered. He seemed to be looking around, trying to locate something. Or someone. “Hey, Biwa demon!”
The demon in question strummed her instrument once more, the fortress going through another disorienting change with the high strung pang of the strings. This time, Kokushibo found himself separated from Kaigaku. He was perched on the ceiling, not too different from an ominous bat.
He observed the scene unfolding from above. The first thing he noticed was that the Biwa demon - Nakime - had parted the hair that normally covered her eyes. Eye . One singular eye, the barely decipherable kanji for “Upper Moon Four” carved into the iris.
That man had already given Hantengu a replacement. Such calculated pragmatism and detachment.
Kaigaku was located on a small platform ledge in front of Nakime. A sacrificial offering. Doma and Akaza had by an odd twist of fate ended up side by side. The latter seemed to be using all of his willpower to not attack the former, if only because he could sense Kokushibo’s gaze piercing through him.
“Akaza-dono!” Doma exclaimed. “I’m so glad you didn’t die! You haven’t even had the chance to challenge me to a blood battle yet!”
“There will be no more blood battles.”
That man’s chilling voice, accompanied by the strike of the biwa, brought another change in positioning. Kokushibo instinctively knelt, with Doma on his right and Akaza on his left. They were located behind and below that man , taken on the form of a well mannered child, didn’t as much as spare them a second glance. Nakime continued to sit in her apathetic devotion on the cushion on his right.
“If you still have energy to waste on something as pointless as blood battles, then you are of no use to me.”
That man seemed exceptionally aggravated.
“As you wish, Muzan-sama,” was Akaza’s simple, harshly blunt answer.
“But of course, Muzan-sama!” Doma said in his perpetually cheerful tone deaf voice. “Right, as always! Focus on killing all the pesky Pillars-”
“Silence!”
That man turned his attention to Kaigaku, who stood before him in shocked and fearful silence. The fool had forgotten to bow. Under Kokushibo’s watchful glare, Kaigaku scrambled to his knees and touched his forehead to the tatami floor.
“Kokushibo,” that man said in a painfully controlled voice. “What can you tell me about this demon?”
He spoke slowly. “This demon… is a former Demon Slayer… Breath of Thunder user…”
“You were the one who converted him.”
Not a question. A simple statement of fact. One that that man did not need a confirmation for. Kokushibo’s role in this judgement had concluded.
Kaigaku hadn’t shifted from his kneeling position. That man looked at him with what could only be disdain. “What kind of worth can something as pathetic as you provide?”
“I- I’ll kill as many Pillars as you want. M-Master Muzan- I’ll serve you with complete and utter devo-
That man cut Kaigaku off with a stab to the chest. “You can quit your groveling if all you are going to do is spout pathetic lies. It is pitifully obvious that you only agreed to become a demon to save your worthless hide. You are a traitor, and a coward.”
Kaigaku screamed as that man pumped his blood into him. Kokushibo watched without a trace of sympathy. “Still, you will make for a decent rank filler. I expect you to serve me without hesitation. Know who you must fear; me, or the Demon Slayers.”
That man withdrew his arm from Kaigaku’s chest. But the squirming demon’s relief was short-lived, as that man proceeded to drag him forward by his hair and begin carving characters into his eyes. Kaigaku’s screams of agony echoed through the twisting maze of a fortress. Blood dripped from his face, coloring the tatami floor scarlet. When he raised his head, still shaking from the shook, “Upper Moon Six” was neatly chiseled into his eyes, blood running down his cheeks, the crimson tears he refused to shed.
No new Upper Moon Five seemed to be joining them. Right. Gyokko had been that man’s favorite. There was no replacing Gyokko.
“Muzan-sama!” Doma piped up, still beaming with that obnoxiously fake smile. “What will we do now that Gyokko and Hantengu are dead? Same old?”
Finally, that man turned to face the remaining original upper ranks. His eyes gleamed with something maniacal. Satisfaction, Kokushibo realized.
“Your pointless quest is finally over!” That man exclaimed. “None of you could ever find that blue spider lily. Well, you don’t need to worry about that anymore.”
Akaza turned his eyes down in shame. It had been primarily his job to locate the elusive plant, after all.
A memory flash played in their heads. Hantengu’s final moments, it seemed. Kokushibo saw a boy jump in to deliver the final blow. A boy with familiar hair and a familiar Demon Slayer Mark.
He looked like Yoriichi.
Akaza scowled more than usual. He seemed to recognize the brat, too. From where?
That man forced their attention away from the Yoriichi look alike and to the background, the washed out afterthought. A demon girl struggling to her feet, her bamboo muzzle coming loose. The burns caused by the scorching sun were healing before their eyes.
“That demon has conquered the sun!” That man seemed ecstatic, grinning and showing off his fangs. “All I need to do is absorb her and I’ll inherit that immunity!”
“I get it!” Doma called out. “We need to capture her and bring her to you! I can do it! I’ll do my best not to bite her myself on the way here!”
In a fluid motion, that man ripped out Doma’s tongue. For all of Doma’s frightening prowess in battle, he really needed to learn to keep his mouth shut.
“You are no longer necessary!” That man roared. “Be grateful I’m not killing you all on the spot for being such miserable failures! With Nakime’s eyes, I will locate her soon, as well as Ubuyashiki and all of those meddlesome Pillars. I’ll destroy the Demon Slayers once and for all.”
That man glared over them all once more. “All I expect from you is to fight in the inevitable battle. Destroy the Demon Slayers. Kill every last Pillar, and the brat with the hanafuda earrings.”
“As you wish, Muzan-sama,” Akaza said with a malicious look of compliance. “I’ll take great honor in killing that weakling.”
Doma’s tongue regenerated, and he smiled once more. “This will be quite fun! I’ll do my best so that you won’t punish me again.”
Kokushibo spoke slowly, with careful consideration put into every word. “We will… finally… destroy any opposition… that you face. You will… finally… reach your goal. We will… be… your humble… stepping stools…”
That man’s perfect, obedient Upper Moons. The perfect demons. Perfect.
~~~
They were all imperfect. That’s why they lost.
Kaigaku, too human. Unwilling to let go of his silly grudge against his old mentor and fellow student. He wasn’t careful enough, and let anger blind him. The end result, getting his head cut off by the successor he deemed to be inferior.
Nakime, not human enough. Just strumming along on her biwa. Perfectly in tune with her surroundings, but completely isolated. Alone. The Serpent and Love Pillars were working in perfect harmony. It was only a matter of time before they managed to kill her.
Akaza, too human. He let himself be killed the moment he remembered his past. He let the Water Pillar and Breath of the Sun user kill him. He had too much human goodness in him. Kokushibo realized that if Akaza retained his original memories, or got them back sooner, he likely would have defected.
Doma, not human enough. He underestimated his opponents because they were humans. Since he was raised as a god, he forgot his human origins. He never considered what sly tricks weaker beings could use, such as the poison the Insect Pillar consumed in hopes he would take the bait. He didn’t fight with his full power, preferring to toy with his prey, resulting in his loss.
Kokushibo was not like the rest of them, though. He was the perfect blend. Inhuman enough to keep his composure in battle, but not so inhuman that he became numb. Just human enough to retain his humility, but not so human he felt empathy.
That’s how he survived for hundreds of years. That’s why he was Upper Moon One, second only to that man .
Kokushibo could not lose anymore. His younger brother was the only one who could have given him a graceful defeat. If Yoriichi had killed him during that blood moon four hundred years ago, Kokushibo would have been content. It would have been a death worthy of him, dying at the hands of the strongest Demon Slayer in existence. Since that was no longer possible, he would not lose to anyone. His pride as a demon would not allow it.
He was composed. He was ready. There was no hate or rage, or any strong emotion for that matter. He simply existed, and the purpose of his existence was to wipe out the Demon Slayers, and bring that man closer to his goal.
Kokushibo stood there, completely void, waiting for his descendant to steady himself and draw his weapon.