In the blink of an eye, another month had passed.
During this month, the entire Demon Slayer Corps was immersed in an intense and lively training atmosphere, filling the training ground with a constant stream of people.
Riezel acted as if nothing had happened and continued using the nine Hashira as sparring partners (punching bags). He trained with them every day, engaging in heated battles.
In this circumtances, one of the Hashira finally succeeded in awakening the Transparent World.
It was none other than Gyoumei, who awakened the Transparent World on the third day of the month.
As the strongest in the Demon Slayer Corps, Gyoumei proved his worth through his actions, inspiring and motivating the other Hashira who hadn't yet awakened the Transparent World. Consequently, the other Hashira redoubled their efforts and training, gradually awakening the Transparent World one by one.
Around the seventh day, Obanai succeeded in awakening the Transparent World.
Around the tenth day, Muichirou succeeded in awakening the Transparent World.
Truthfully, it was no surprise that they were the ones who awakened the Transparent World first.
Of course, the other Hashira didn't want to be left behind either.
Around the thirteenth day, Sanemi succeeded in awakening the Transparent World.
Around the sixteenth day, Giyuu succeeded in awakening the Transparent World.
Around the twenty-second day, Kyoujurou succeeded in awakening the Transparent World.
By this point, out of the nine Hashira, six had fully awakened all three abilities.
Only Shinobu, Mitsuri, and Tengen were left, seemingly not cut out for this, as they still hadn't succeeded in awakening the Transparent World.
Without a doubt, this left the three of them feeling quite dejected. Even Shinobu, who usually had a smile on her face, could be seen with a hint of gloom in her eyes.
Mitsuri often looked tearful, which prompted a certain Serpent Hashira to secretly give her extra training sessions, personally teaching her the principles of the Transparent World.
Tengen, on the other hand, spent his days muttering to himself, sitting in a tree with his arms crossed, eyes closed, lost in thought.
Evidently, the successive successes of their comrades made these three increasingly anxious.
Seeing this, Riezel couldn't do much about it.
He had said it before, the Transparent World was different from the other two abilities, as it was not something you could just get whenever you wanted.
If it really couldn't be done, then it couldn't be done—there were no shortcuts.
At least, in Riezel's view, if Shinobu and the other two hadn't awakened the Transparent World by now, it was probably a lost cause.
In the end, they could only depend on themselves.
During this period, Kagaya suddenly summoned Riezel to meet with him.
When Riezel saw Kagaya again, he was in a rather dire state.
Now, Kagaya was completely bedridden, spending his days lying under the blankets, where even speaking took considerable effort.
It seemed he was truly nearing his end.
"I probably don't have much time left, so I'll say what needs to be said..."
Kagaya spoke with the demeanor of someone who could pass away at any moment.
Riezel frowned deeply as he heard this, but he could do nothing.
In truth, he had already attempted to treat Kagaya.
'Dia Fratel' was, after all, among the best healing magic, capable not only of treating injuries but also of dispelling curses.
With this magic, Riezel initially believed he could cure the illness plaguing Kagaya, as the disease afflicting him was a curse—a curse born from Muzan.
In the Heian period a thousand years ago, Muzan, who had not yet become a demon, was actually a member of the Ubuyashiki family.
In other words, there was a blood relationship between the Ubuyashiki family and Muzan.
After Muzan became a demon a thousand years ago, the Ubuyashiki family seemed to collectively fall under a curse. Regardless of who they were, the children born to them would become weak, sickly, and die soon after birth.
Especially boys, with a very high chance of early death, almost causing the Ubuyashiki family's bloodline to be severed.
Later, generation after generation, men in the Ubuyashiki family would marry women chosen by a priest in an attempt to delay the curse and prolong their lives. Even so, no one from the family could live to be over thirty years old.
Because of this, every member of the Ubuyashiki family was weak and frail, and they died early without exception.
Kagaya was only twenty-three years old this year, but he had been seriously ill for some time and was expected to pass away soon because of this serious illness.
As Riezel believed that Dia Fratel could dispel curses, he thought it might be able to remove the curse from Kagaya.
Unfortunately, he failed.
Apparently, this curse was not imposed on individuals but on the entire family's bloodline.
In other words, if Riezel wanted to dispel this curse, he had to completely remove the curse from the entire members of the Ubuyashiki family at once.
However, not only was Muzan himself a member of the Ubuyashiki family, but he was also the source of the curse. Hence, as long as he was still out there, even if Riezel removed the curse from every member of the Ubuyashiki family, the curse would only return to them, like a recurrent ulcer in the bone.
Clearly, this meant that the curse on Kagaya could not be dispelled and that his body would only grow weaker over time.
Kagaya calling Riezel this time was evidently to leave a will.
First, Kagaya gave Riezel some information.
"Recently, incidents of human disappearances have been frequent in towns everywhere..."
From Kagaya's mouth, the missing people were mostly violent offenders or martial artists with exceptional combat abilities, even those who had committed sins deserving execution.
Without exception, they all vanished suddenly without any warning. Some disappeared from their homes, while others never returned after leaving, causing quite a stir in society.
According to the intelligence network of the Demon Slayer Corps, these people had brief encounters with demons before their disappearances.
Initially, the Demon Slayer Corps believed they had been eaten by the demons, but later realized something was amiss.
After all, these people shared a common trait—they either possessed combat abilities or exhibited some tendency toward violence.
Since this information raised serious concerns within the Demon Slayer Corps, it eventually reached Kagaya.
"Also, not long ago... an entire town to the east suddenly had everyone disappear—men, women, children, thousands of people, all gone overnight without a trace..."
Kagaya relayed this information to Riezel, who furrowed his brow.
"So many people disappearing all at once?"
Any sane person would know this was definitely not a good sign.
Humans were, after all, a precious resource for demons, no matter how you looked at it.
Not only did they serve as food, nourishing demons and enhancing their power, but they could also become demons themselves if Muzan gave them his blood, immediately shedding their human identity and joining the ranks of demons.
Now, with a large number of humans disappearing en masse, Riezel couldn't believe it was anything other than the handiwork of demons.
Whether they were consumed as food, used to increase the power of demons, or transformed into demons for combat power, it was all extremely bad news for the Demon Slayer Corps.
"I can feel Kibutsuji Muzan's power increasing rapidly..." Kagaya continued.
It was precisely because of this that his physical condition was deteriorating this fast. It was a manifestation of the curse running through his bloodline.
When the curse strengthened, it meant that Muzan, the source of the curse, was becoming stronger.
"Be careful..."
Kagaya lay in bed, his face covered with a towel, obscuring his almost decayed face.
"We are preparing, and so are the demons..."
"A great battle is approaching... the decisive battle that will determine the future between humankind and demonkind is getting closer..."
"And you... you are the key to this decisive battle..."
With what seemed like his last ounce of strength, Kagaya smiled and left his final words for Riezel.
"I don't know if I can hold on until that day... If I can't, then the Demon Slayer Corps and everything else will be in your hands, Your Excellency..."
Leaving behind these words, Kagaya lost consciousness.
"Master Kagaya!"
Kagaya's wife, Amane, rushed in with their children.
Riezel also approached, glancing at Kagaya's body, realizing he had only lost consciousness, not passed away. Still, his aura was as faint as a dying candle in the wind, on the verge of extinguishing.
In fact, after Riezel awakened the Transparent World and took a glance at Kagaya's condition, the sight was so unbearable.
'Not much time left, huh...?'
Riezel understood this clearly, quietly observing the tense efforts of those around Kagaya for a moment before silently leaving the room.
On the same day, all the Hashira unusually did not appear at the training ground. Instead, they all came here, guarding Kagaya throughout the day.
===
Nighttime.
At this moment, Riezel sat on his house's veranda, looking out over the courtyard and watching the bright moon in the night sky.
Even though the moon hung high and clear, it gradually took on a crimson hue—clearly a lunar eclipse.
===
Meanwhile, in the castle with an inverted space and bizarre layout, the blood-stained Demon King, Kibutsuji Muzan, appeared silently.
He also gazed at the night sky, at the bright crimson moon, the traces of blood on his lips stark against his pale complexion.
"It's time..."
Muzan revealed a cruel smile.
"It's time to fulfill this thousand-year-old wish..."