Disclaimer:

I do not own nor claim all the rights to 鬼滅の刃 | Kimetsu no Yaiba | Demon Slayer; all rights are reserved to its respective creator, Koyoharu Gotōge. This is purely a work of fiction; names, characters, businesses, events, localities, and occurrences are all extrapolated from the author's writings and imagination or utilized in a fictitious manner. As such, any direct or indirect references to actual entities, dead or alive, or events do not, in any shape or form, resemble the opinions of the author.

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"..." = Dialogue

'...' = Internal monologues

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"Junnosuke..." a tender voice softly beckoned.

Junnosuke steadily lifted his eyelids open, bringing his mother into his line of sight.

The teenage boy was perched seiza-style adjacent to the mother's futon, where she was seated in an upright position.

The mother was staring straight ahead, away from where her son was situated.

"Are you tired?" she asks with worry. "You have been dozing a lot today..."

The eldest son, not wanting to evoke an insipid appearance, straightens his back and lifts his head in order to add formality to his posture.

"I'm perfectly fine, Mother," Junnosuke reassures diligently. "It's just that the wood chopping yesterday with Father was unusually tiring."

The mother turns her head to the source of the sound, permitting her to face in the direction of her son's current disposition.

"Tell your Father to not pile on your workload," she suggests.

"It's alright, Mother. Besides, Father is teaching me useful things about the trade," Junnosuke answers assiduously.

The Mother lets out an amiable grin, "You don't have to always push yourself, even if you're the firstborn."

"It's the duty of the eldest son to help the Father in caring for the family," Junnosuke was punctilious in invoking the key tenets of traditional family values.

"Yes, but you're still a young boy... You don't have to carry that burden alone. The rest of us aren't completely helpless, you know?" the Mother quips in a placating and soothing manner, exuding the warmth of a mother's love.

"Ah... right..." the son replies hesitantly, as he treated the words uttered by his mother as those carrying tremendous wisdom—even if they contradicted his beliefs.

The Mother smiles warmly, "You and your father are so similar in many ways..."

"Me and Father?" Junnosuke questions.

"Mhm," the Mother hums in response, "both of you are so determined to protect this family. Even if you have to do it alone..."

"..."

"May I request a favor, Junnosuke?" she suddenly brings up.

Junnosuke was a little startled to hear this, but he complied nonetheless, "Of course, Mother."

"Please look after your father, Junnosuke..." she spoke faintly.

"Look after Father...?" Junnosuke said in confusion.

"Yes..." the Mother confirmed. "He tries to always put up a strong face for the family and does everything on his own... But he's a soft and fragile man, and I worry that he'll go to extremes to protect what he loves..."

She frowned, "I don't want to see him suffer... He deserves all the happiness in the world, and I want to see him smile..."

Never had the eldest son witnessed such a doleful expression manifest along his mother's lineaments. It was a strong indication of the degree to which such sentiments resonated with her heart, showing just how much she loves her husband.

"Mother..." Junnosuke was at a loss.

"Can you promise me that, Junnosuke?"

Junnosuke inhaled deeply from the nose, and then exhaled slowly from the mouth.

This was something she could ask of only him. He knew that.

"As the eldest son of this family, I will do my utmost to fulfill the wishes of my mother," he proclaimed with a fastidious observance of etiquette and proper composure.

The Mother's countenance brightened up, "Now, now, let's not get too formal."

"But—"

"You're still my little baby boy, Junnosuke. No amount of formality will change how cute you are!" she exclaimed.

"M-Mom!" Junnosuke protests sheepishly.

"Aww, you're such a cutie pie!"

"S-Stop that!" his face reddens from the embarrassment.

The Mother giggles, "I love you, my son."

Junnosuke, seeing this, relaxes his expression and smiles softly.

"Love you too, Mom."

..

..

..

..

"Junnosuke," a firm voice beckoned.

The boy was knocked out of his trance, shifting his gaze to his father.

"Stay alert," the man reminded.

"Yes, Father," Junnosuke acknowledged.

The two of them were trekking through the woods, transporting a heavy load of material and appliances they had exchanged for their freshly-made sandglass at the market.

With business conducted for the day, they were now bound for home.

The sweet scent of the after-shower dew tickled their noses, and the patchy drizzle of water drops from the sky occasionally patted their straw-woven Kasa hats.

It was very foggy, but it was still daytime nonetheless—they could still look upon the path ahead without much concern for any erroneous alterations to their location.

The boy trudged through the muddy path with great labor, with the load carried on his back adding more weight to this downward force.

The boy panted heavily as the mud soaked into his socks, each step forward was tantamount to an unsustainable exertion of energy—draining the muscles of strength.

Before long, the boy would fall victim to this burden.

*Slip*

"Ah—!" the boy tripped, set on a trajectory to fall incorrigibly to the ground.

*TUG*

The father tightly grips the boy's wrist, preventing his descent to the begrimed floor.

"I got you, my boy," the Father assures.

He then pulls his son, putting him up on a solid footing.

"Don't be daydreaming," the Father warns.

"Sorry Father..." Junnosuke was huffing and puffing.

Taking notice of his son's fatigued state, the Father promptly and correspondingly grabs a hold of a portion of the load resting on the boy's back.

"Get yourself together, you're the eldest son," the Father admonishes.

"Sorry..." the boy mumbles, crestfallen.

The Father subsequently sighs, relenting at the sight of his son's downtrodden expression, "Junnosuke, do you know why I'm hard on you compared to your siblings?"

"W-Why?" the boy answers timidly.

"Because you're the first-born and the eldest son," the Father states.

"You are responsible for your family, as the rights of primogeniture lie within you. You have got to look out for your siblings and your mother... Especially when I'm not around," he expounds.

"I am...?" the boy asks.

The Father nods, "As the eldest child, you are duty-bound to protect your younger siblings and your vulnerable mother at all costs..."

"You must protect their smiles at all costs... Even if you have to kill me to do it..." the Father adds wistfully.

The boy's eyes widened.

"Promise me that, Junnosuke," there was great anguish in his tone.

Before he could answer, the voices faded.

And the memories were washed away by the coming tides of abeyance and sorrow.

The soul was hollowed and the spirit confined to the chains of the past. The recollections of happiness were now the burdens of the present.

They will not go away until the oath is fulfilled.

But, until then, happiness will be a forlorn memory.

..

..

..

..

..

..

*Tap* *Tap*

Zaiaku-kan steadily lifted his eyelids open, bringing this empty chamber into his line of sight.

The Demon of Guilt was bestirred from his reverie at the resonance of distant, echoey footsteps.

*Tap*

The strides were getting louder and, thus, nearer.

*Tap*

A figure emerged from the darkness, donning only his Demon Slayer uniform—his signature mismatch haori was missing.

*Tap*

The man finally ceased his march, standing about 20 feet (6 meters) from the large boulder the Demon of Guilt had taken the pleasure of settling on.

Within this large chamber of twisting pipelines, little springs of sewage water, and lush greenery intermittently spread, two men stared at each other with a hardened look.

"You arrived," Zaiaku-kan announces.

"I didn't think we would meet again under such circumstances... much less have a reunion in the first place," Giyuu's face expressed displeasure.

"Sabito," he glared.

"Heh, so that's the name of this body," Zaiaku-kan contrives an evil grin.

Indeed, the Demon of Guilt had cladded himself with the physical incarnation of Sabito—the same Sabito who died years ago in the Final Selection examination.

Moreover, he was wearing a Warding Mask—the same mask that Urokodaki Sakonji had gifted Sabito all those years ago. Nevertheless, despite the inscrutable face, Giyuu knew it was him.

He could never forget the mask, the hair color, the clothes, and the sound of his voice.

This was Sabito.

"What are you exactly," Giyuu demands an explanation.

"Well, you can probably guess it already. But I'll tell you anyway," the Demon of Guilt scoffs.

Giyuu's brows furrow.

"I am a formless being, meaning I have no physical body," Zaiaku-kan starts.

The Water Hashira evinced a look of perplexity.

"Instead, my powers permit me to take upon the form of any human being that my opponent harbors some form of regret, guilt, or anxiety towards. Usually, this means individuals that are emotionally linked to the enemy in question, allowing me to exploit their feelings and fragile state of mind in the form of said emotionally-attached characters," Zaiaku-kan clarifies.

He continues, "For example, with your beloved Shinobu, she felt intense guilt for letting her sister die. So, accordingly, I took the form of her sister, which made it really easy to catch her off-guard and impale her with a blade..."

Giyuu's ire was provoked upon hearing how Shinobu was terribly deceived and how it incurred a great toll on her mental and emotional health.

"You're sick," Giyuu snarls.

"An additional benefit is that I slowly collect the memories of the body. So, I'm allowed to taunt my prey as well."

A vein emerges along the Water Hashira's temple, "That's why you look like Sabito..."

"Indeed, Tomioka Giyuu. I haven't yet acquired all of the memories, but I can already tell that you two were the best of chums," the Demon of Guilt mocks.

"Oh, and there was a Makomo, wasn't there? I'm sure she's doing JUST FINE nowadays," he adds fuel to the fire.

Giyuu gritted his teeth, having to quell the urge to immediately engage the enemy, "Fuck off."

"Haha," Zaiaku-kan laughs scornfully, "this is how you treat someone who divulges such sensitive information?"

"Why are you telling me this in the first place..." Giyuu questions with suspicion.

"Since you were so willing to abandon your beloved Shinobu," Zaiaku-kan jeers, much to the chagrin of Giyuu, "I will satisfy my end of the deal and tell you all that is to be known about this happy family of demons."

"What is there to know; I'm here to kill you people anyway," Giyuu counters.

"What is there to know? EVERYTHING," the Demon of Guilt emphasizes heavily. "You are dealing with matters that extend beyond your average skirmish with one of Kibutsuji Muzan's underlings. My Father is far more powerful and all-knowing than you could possibly think."

"What do you mean."

"I mean my Father is not even human in the first place. Unlike Kibutsuji Muzan, he was BORN an oni—a demon originating from its rightful birthplace, Yomi."

..

..

..

..

"AGH!" Shinobu grunted in pain as she attempted to carefully traverse the tunnel.

Using the walls as support, she slowly limped her way through the slough, hoping to catch up to the man she had only recently confessed her unconditional love.

But the severity of her wounds and injuries made this normally simple task an arduous one for her broken, bandaged body.

"Giyuu... Why..." she spoke plaintively, the echoes of her voice ostensibly falling on deaf ears.

"Why did you leave me... You promised that you wouldn't leave... You said you would always be there..." her voice increasingly quivered with greater rapidity.

"Why did you leave me...?" her heart ached at the prospect of this great woe.

History was repeating.

Just like when Old Giyuu sedated her and took off to fight the demon alone, here and now Giyuu was nearly emulating the same exact succession of events.

And if the outcome is to resemble what she saw in the future, then her spirit—hitherto enlivened by the outpouring of love and affection presented by Giyuu—will truly be destroyed without remedy.

She absolutely cannot let Giyuu do this alone.

She cannot watch him risk his life.

She cannot let him die in her arms again...

If he dies, then there is nothing for her.

"Giyuu!" she cried out in her desperation.

Nothing.

The eerie halls of this sewage system will not disclose the location of her beloved.

*Thud*

"No... No...!" she collapsed on her knees.

"Don't leave me... Please don't leave me... Giyuu!" Tears welled in the corners of her eyes.

Nothing.

"No..." she sobbed.

She buried her face into the palms of her hands, "Giyuu... I love you... I love you... Please answer me..."

Nothing.

The bitter, unforgiving grip of silence gnawed away her heart even further, displaying the extent to which the Insect Hashira's grief over Old Giyuu's death had not fully healed.

She pleaded for her beloved to return, but he would not.

And, even worse, she cannot scurry about to discern his exact location; she is completely and utterly helpless in this damned situation.

Just like with Old Giyuu.

The darkness begins to envelop her as she drowns in her sorrow.

Her paranoia was getting the better of her; after a lifetime of watching her loved ones die before her, she cannot accept another death.

But the grim reaper inched ever closer to him. The premonitions of his demise, the visceral imagery of his lifeless body, and the distressing final moments of his life.

She was beginning to imagine it all, because she had already witnessed it once and again on his deathbed.

The tocsin of death rang loudly in her ears, even if she tried to cover them with her hands.

Death. Death.

Her parents, Kanae, and Old Giyuu.

It was biting into her bones, eating away her flesh.

She could already imagine his blood on her hands.

The lifeless eyes. The pool of blood accumulating beneath his corpse.

She was just about to witness the full picture.

"Are you ok?" a light, reassuring voice asked.

Shinobu stopped for a moment.

She then stole a glance at the figure standing beside her.

Her eyes dilated with shock.

The Insect Hashira instantly recognized the short girl.

"You are..." Shinobu whispered.

"My name is Makomo," she smiled warmly. "Giyuu is very lucky to have you by his side, Kocho Shinobu."

..

..

..

..

"He was born a demon??" Giyuu was flabbergasted.

This defied the conventional understanding of demonic creatures: that their blood is simply the derivative of Muzan's, whose powers likely came from an unknown source.

Yes, Muzan was initially human. This can be corroborated by the records of the Ubuyashiki family, the founders—and current leaders—of the Demon Slayer Corps: Muzan turning into a demon is what caused a terrible curse to befall the Ubuyashikis in the first place.

But to be born one from the get-go?

That was inconceivable.

"Why yes, although it is more accurate to say that he was 'created' rather than 'birthed,' if we were to be pedantic," Zaiaku-kan confirms.

"Created?"

"Where do you think demons come from? Are they the byproduct of some evil curse or a spontaneous biological process? No, they are spawns of the Goddess Izanami," Zaiaku-kan reiterates.

Izanami-no-Mikoto, the Creation Goddess who—alongside her husband Izanagi-no-Mikoto—brought about the formation of the Japanese Home Islands.

She is the mother goddess, the primordial deity who also gave birth to the likes of the sun goddess Amaterasu, the moon deity Tsukuyomi, and the storm god Susanoo.

She and her husband conceived all the Kamis of Shintoism.

At least, that's what Shinto Creation Myth says.

"Izanami...?" Giyuu isn't particularly religious, so he was stunned to hear this.

"That's right. Upon giving birth to her last child, the fire god Kagutsuchi, Izanami was severely burned and sent to the Land of Yomi—the underworld. There, she was turned into a hideous creature: a rotting living-dead corpse," the Demon of Guilt explicates meticulously.

He proceeds with the explanation, "Such was the case that when her husband Izanagi came to retrieve her, he ran away in horror at the terrible sight. As Izanagi abandoned his wife, Izanami shrieked in anger at the betrayal, 'Every day I shall kill one thousand people in the lands we created.' Izanagi, in turn, replies, 'Every day I shall create one thousand five hundred people.'"

"Yes, I know. This is common knowledge," Giyuu contends.

"But did you know that, in adherence to her own promise, Izanami created the Oni to carry out her wish?" Zaiaku-kan astutely points out.

"Demons... She created demons..." Giyuu realized.

"The Curse of Izanami. One thousand humans are to be killed every day in these lands. Killed by Demons," Zaiaku-kan states grimly.

"That's why demons exist..." Giyuu mutters.

"And that's how my Father was created. He was born as an immortal Oni in the Lands of Yomi."

"Then how did—?" Giyuu was about to inquire.

"How did he leave Yomi? How did he conceive children? With a wife?" Zaiaku-kan finishes for him.

"... Yes."

"I don't know."

"You don't know?"

"Yes, I just don't know," the Demon of Guilt repeats.

"There are certain things about my Father that I simply do not know. How did he escape Yomi and enter this world? I would guess a directive from the Curse of Izanami is a sufficient explanation. However, my Father was HUMAN when I was born. And I don't know how or why. Much less, how he met my Mother," he clarifies.

"I see..."

"What's more confusing is that he aged; my Father is supposed to be immortal, but he aged nonetheless. Although, that technically ties back to him being human—which I don't know the reason for anyway."

Not even the Demon of Guilt is aware of the true nature of his Father's history or powers.

Giyuu felt a cold chill down his spine at the thought.

Zaiaku-kan exhales, "In any case, my Father—his name being Akio—and my mother, Himari, conceived four children. I was the eldest, Junnosuke. Then, a daughter: Eiko. You might know her as Haji. Following that, another daughter: Etsuko—Kanashimi. And finally, a son: Isamu, who was Osore."

"My family was a happy one. Even though my Mother was blind, my Father seemed to love her quite a lot—and it was duly reciprocated. My siblings and I loved our parents just as much... These were by far the happiest times of our lives..." Zaiaku-kan reminisced mournfully.

"..."

"Until THAT happened..." his voice darkens.

"What happened?" Giyuu queries.

"Apparently, my Father worked for various lords before he met my Mother. He was especially good at KILLING. But he suddenly retired to raise a family... Of course, being such a huge asset, he was also a risk. So, one of these lords wished to deal with him swiftly..."

"So they killed us all..." he growled angrily. "I remember that day so clearly it is etched into my eyes."

"My mother was killed first, trying to protect me from a stray arrow... It pierced her heart, instantly killing her. Father was too busy fighting them to immediately notice this..."

"Eiko was next... She was... raped to death..." Zaiaku-kan's voice shook.

"Etsuko was stabbed through the heart."

"And Isamu, who was just around six years old by then, was beheaded."

"..." Giyuu felt sick to the stomach hearing this.

Even if they might be his enemies, their deaths are no less gruesome and abhorrent.

"After restraining us, they subjected me and my Father—the two people who were actively fighting back—to death by immolation... We were burned to the crisp..."

"..." Giyuu remained silent.

"However, something happened. By burning Father, he somehow reverted back to his demonic body... My father became a demon again..."

"And, emerging from the flames, he proceeded to kill everyone in his rage. But he didn't stop there, he went directly to the Lord and massacred his entire Clan—he spared no one, not even innocent lives such as the women and the children."

"That was when Utsuro arose from the ashes of his family and the blood of the innocent."

"Utsuro..." Giyuu restated.

"My Father goes by that wretched name nowadays," Zaiaku-kan enlightens.

"I see..." the Water Hashira acknowledged.

"So, in the aftermath of that bloodbath, my Father tried to desperately revive his family; he tried to make us demons in an effort to undo the damage that was done. To accomplish this, Utsuro split his soul into different slices, attaching each part to the corresponding body," Zaiaku-kan pressed on.

"However, it went terribly wrong..." he had a scowl on his face—Sabito's face.

Giyuu wasn't able to see it due to the Warding Mask, but he could sense it.

"First was Isamu. Because he felt unadulterated fear in the final moments of his life, and because he was beheaded, Utsuro's soul turned him into a mindless monster who cannot think logically. That's how Osore was born."

"Next was Etsuko. Because she felt the extreme grief of losing her family, and because she was without a functional heart, she was turned into Kanashimi—a heartless, sullen being without any positive emotions."

"And then, Eiko. Due to her being subjected to rape, she felt shameful for losing her innocence and chastity as a woman. So, Utsuro made her into Haji—a shameless, cruel demon..." There were hints of intense sadness in Zaiaku-kan's voice when he spoke of Eiko.

"As for me... Because I had no physical body, and... because my mother died for me... Utsuro's powers made me into a wandering spirit—without shape or form, just a cloud of regret and guilt... I have forgotten what I looked like... It's been over a millennium now," the Demon of Guilt spoke with a melancholic tone.

"But... while he managed to 'revive' us children, my Mother couldn't be resurrected... This enraged my Father. She was the one he wanted back the most..."

"On that day, Utsuro, my demon siblings, and I all vowed to bring back Mother. I was so blinded by my guilt, anger, and sadness that I didn't really think it through."

"Think what through?" Giyuu touches on this.

"That the quest to revive my Mother would be so bloody in nature..." Zaiaku-kan's voice eerily echoed.

He continues, "Utsuro relied on sacrificial rituals in an attempt to somehow revive Mother. All of them failed. So, we increased the number of victims. From just one sacrifice to thousands, we spent the last 1,000 years building a whole business down here. 'Wishes for sacrifices.'"

The Water Hashira was able to quickly recognize that phrase by memory.

..

"That was the compromise. 'Wishes for sacrifices,' is the saying around here. It's kind of like a fucked-up business."

..

Old Man Yamashita Hayashi's words.

Giyuu remains eternally thankful for his sacrifice.

"We promised to bring delusions of pure bliss into reality for people, and they, in return, would offer their souls for these rituals. It was a perfect set-up... but it still wasn't enough. Our Mother was to remain dead," Zaiaku-kan elucidates.

"That is... until the world started changing above," said the Demon of Guilt.

"Change?" the Water Hashira inquires.

"The Meiji Restoration. The moving of the Imperial House from Kyoto to Tokyo. Industrialization. Suddenly, Yokohama had a booming population. The city's residents swelled into the millions. Urbanization has permitted a large number of people to be concentrated in a small area," Zaiaku-kan explains.

Giyuu didn't know where he was going with this.

"About two months ago, Utsuro had an idea. With so many people living within a smaller surface area, it could be possible to conduct a ritual that instantly consumes a million souls simultaneously."

The Water Hashira's eyes widened, "You don't mean—"

"Yes," Zaiaku-kan nodded, "Utsuro intends to sacrifice all the 1 MILLION denizens of Yokohama in an attempt to bring back my Mother—his wife."

"T-That's crazy! Not even Kibutsuji Muzan has attempted something as large scale as that!" Giyuu vociferates.

"Precisely. And that was when I realized just how twisted my Father had become. And not just him, but my siblings too—they concurred with the plan. That was when I realized that we were reaching the point of no return..."

This was bad.

The scope of this mission had now gone beyond the Water Hashria's wildest imaginations.

No, this was no simple abduction case. This was something worse. If Utsuro wasn't stopped, then mass genocide could occur.

One MILLION.

That is a thousand of one thousand. A ten of one hundred thousand.

Ten raised to the six powers.

That many people are at risk.

The weight of the world—no, the weight of the universe—now fell on Giyuu's shoulders. If he fails, then he will be personally responsible for the largest mass killings in Japanese History—no, one of the largest in WORLD history—and the largest number of deaths caused by a demon.

If Giyuu failed here, he would fail not only the Demon Slayer Corps but ALL of Japan.

The ramifications of this action are too great for him to even process completely and correctly. There's just so much baggage involved in this.

This was really bad.

Giyuu was starting to panic.

"This plan was so absurd that even I had to oppose it. But, apparently, I was the only one with some humanity left," Zaiaku-kan carries on. "I suppose my powers of constantly adorning different forms along with looking into different human memories and emotions have allowed me to retain a certain amount of humanity..."

"..." Giyuu, now staring downwards, was still in the midst of an internal crisis.

"And that's when I knew... that this family had to be destroyed at all costs..."

The Water Hashira looked back up, stunned, "You... want to defeat your own family...?"

"Who do you think filed that initial report to the Demon Slayer Corps, the same report that got you and the Insect Hashira deployed here? A regular human? No, Utsuro would've killed them instantly. But a demon with shapeshifting powers? Absolutely. And that's why I owe you people an explanation; I was the one that sent you guys here in the first place."

Another striking revelation.

The Demon Slayer Corps wasn't tipped off by some brave citizen seeing justice in the injustice of this sinister town.

No, they got tipped off by a demon!

A demon!

Nothing was making sense anymore.

"I've been testing you two since you got here. Whether it is through visions, premonitions, taking the form of your father and haunting you, or anything else, I was trying to see if you two were capable enough to somehow convince my father to abandon the plans. You two were my fail-safe."

The comment regarding Giyuu's father irked the Water Hashira by a bit, but he did not wish to inquire any further into that matter.

"Although, this is after who-knows-how-many tries..." Zaiaku-kan muses.

"... What?" said Giyuu.

"Ah, right. I forgot to tell you," the Demon of Guilt realizes. "Utsuro is unbeatable not for the mere fact that he's a bona fide demon from Yomi. No, he's unbeatable because of his Blood Demon Art."

"What's that?"

"The Eyes of Prognostication. The single most powerful Blood Demon Art on the face of this earth," Zaiaku-kan answers.

"Why's that?"

Zaiaku-kan shifts his seating posture to a lower one, "They allow the user to do three things: peer into someone's future, peer into someone's past, and even travel back to a single point in the past."

"It destroys all scientific understanding of space and time, but it's a gift granted by the Goddess of Creation herself. He likely activated them after the entire family died—during his 'rebirth' as a demon."

"It's the reason why you and your partner had so many premonitions of the future whilst also being able to relive the past. Utsuro's time abilities grant him the knowledge to undertake such depictions. And, because we are linked to him, we children are also given some of that time-related power. Although, that's mostly relegated to dreamscapes for us," he adds.

As if the plan to kill one million people or the fact that a demon sent them here wasn't enough, Giyuu now learns that there's a demon with time-manipulating abilities.

This could not get any worse.

"How? What? Why?" Giyuu threw a flurry of questions.

"Like I told you, Utsuro is not your average demon. He's a deity-like being that transcends time and space. You will never be able to defeat him."

"How would you know?'

"Because I've tried more times than you could count, slayer," Zaiaku-kan angrily rebuked. "The most important power the Eyes hold is the ability to travel back to a single point in time. Unfortunately, the point in time determined is arbitrary. Therefore, whenever it has been used, it only sends the user back to the moment my siblings and I were reborn as demons."

"Thus, after learning about Utsuro's plan to sacrifice 1 million lives, I chose to exploit this power in order to reset the timeline. That way, I hoped, I could somehow change the new timeline such that Utsuro wasn't committed to this insane plan."

"However, the two conditions for that power are for the original soul to be made whole again and that the user to have possession of the Eyes in the first place. In other words, because Utsuro's soul is scattered across me and my siblings, I had to repeatedly kill them, kill Utsuro, gouge out his eyes, and then kill myself. That way, because I killed my family and 'took' their souls, the power would be vested in ME, and I would return to the moment I was 'reborn.'"

"Essentially, the user needs to control all parts of the soul and needs to have the eyes in order for the spell to work. By killing my family, I was able to acquire the souls. Then, by gouging out Utsuro's eyes, I had control of the eyes. With these two conditions met, I could go back to that singular point in the past."

"But..." Zaiaku-kan clenches his fists in frustration, "Each time I tried, it would be the same result no matter what I did: Utsuro determined that the only way to bring back Mother was to initiate the 1 Million sacrifices ritual."

"So, I had to restart the timeline each and every time. Kill Osore, kill Kanashimi, kill Haji, and kill Utsuro. And, after taking Utsuro's eyes, I would kill myself to activate the spell, thereby going back in time. I don't know how many cycles I've been through, but, at some point, I realized that this wasn't going to work; Utsuro is simply too obsessed with reviving his wife."

"Do you know how many times I had to kill my own family with these two hands?"

"So there have been multiple timelines?" Giyuu asks.

"Yes. But those are all the failed ones—the ones where I kill my family and myself," Zaiaku-kan answers.

"Why did they fail? Didn't you succeed in stopping Utsuro from initiating his plans to kill a million innocent lives?" Giyuu questions.

"Because..." the Demon of Guilt whispers. "I want my family to be set free from the bondage of this curse... I want my father... to be free... Because that's what I promised to my Mother."

"I see...' Giyuu nodded, sympathizing with his lofty objectives.

Then, something hits him, "Doesn't that mean you're on our side?"

"Technically, yes," Zaiaku-kan answers.

"Then why are you trying to kill us?"

"Because you two killed my siblings. You've 'stolen' their souls from them. Without the souls, I cannot reset the timeline. And I've already determined this timeline to be a complete failure."

"Why is this timeline a failure? Shinobu and I managed to defeat three of your siblings! With your help, we could defeat Utsuro—!" the Water Hashira argues.

"No, Utsuro would still win."

"Then how did you defeat him in all the other timelines?!" Giyuu exclaimed.

"Because he let me win. To beat him, I take the form of my Mother when facing him... so he immediately capitulates to his fate without a fight," Zaiaku-kan rationalizes, albeit with a guilty conscience—it is a cruel fate to be killed by the very wife you are trying so hard to resurrect.

"Utsuro doesn't have to do ANYTHING to win. He's perfectly fine with resetting the timeline for God knows how many cycles because he's so determined to revive his wife anyway. Besides, I don't want to defeat him, I want to save him," he further clarifies.

"I naively thought that the Demon Slayer Corps would change anything. And I was actually feeling optimistic when you two managed to free Isamu, Etsuko, and Eiko from the Curse of Izanami..."

"But now, especially with those injuries and broken bones, you two stand no chance against Utsuro. You've both greatly disappointed me! The only solution now is to reset the timeline," the Demon of Guilt asserts.

"I highly disagree," Giyuu opposes.

"Well, of course you would. I'm trying to KILL you BOTH!"

Giyuu unsheathed his Nichirin Blade from the scabbard, "You're not getting anywhere near Shinobu."

"Oh? You intend to fight me? Your best friend?" Zaiaku-kan taunts.

"You wish to save the lives of millions, but you still resort to petty tactics employed by demons. You're an odd one," Giyuu retorts.

"Because I AM a demon. I still CRAVE blood! I alone have killed countless lives over the last millennium!"

"Then you will pay for your sins," Giyuu assumes a battle stance.

..

..

..

..

Shinobu and Makomo were both seated, reclining against the concrete wall, as the latter took the liberty of immediately sitting next to the Insect Hashira without much discussion—it just happened spontaneously.

And now, Shinobu was sitting right next to a ghost.

Or, possibly, a demon. After all, she doesn't know if Giyuu has actually engaged Zaiaku-kan yet.

The Insect Hashira glanced hesitantly at her interlocutor, "Are you supposed to be a ghost...?"

"Hm... Technically, I'm supposed to be a spirit," Makomo replied nonchalantly.

"You're a spirit?" Shinobu was a little surprised.

"I was suddenly summoned here... so it can only mean one thing..." Makomo quickly surmised.

"What's that?"

"Sabito is here as well... and he's going to confront Giyuu head-on," said Makomo.

Shinobu instinctively frowned, "He's... going to fight Giyuu...?"

"Yes."

"Will Giyuu win??" Shinobu asks in desperation, panic and heightened anxiety beginning to engross her senses—she is terribly worried for her beloved.

If Giyuu is fighting his own best friend, then this could may as well be the most difficult and painful match of his life.

Shinobu knows how emotionally damaging it was to be stabbed by her own sister, even if that was a demon.

So this might as well be Giyuu's undoing if he can't handle this well.

Makomo paused before responding, "... I don't know. But you tell me this: do you have faith in him?"

"Faith...?"

"Because, if you do," she smiles, "then he will win for sure."

Shinobu's eyes widened, "... I see."

"Then I can only trust him."

..

..

..

..

As he promptly stands on his two feet, looking down upon Giyuu atop the boulder, Sabito unsheathes his blade from the scabbard.

"Tell me, Water Hashira, will you be able to kill your best friend again? Do you have the will to do so?" he taunts.

Giyuu's face corrugated.

"Then come, fight me if you can. Decide whether you will spill the blood of your best friend once more," said Sabito.

"I will do anything to protect what I love. Your intentions to hurt her is all the motivation I need to fight," Giyuu declares.

"We shall see, Giyuu," Sabito assumes a battle stance.

It was to be a clash between two enemies.

Two rivals.

Two students.

And two best friends.

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If you have any questions / want any clarifications regarding the explanation of the powers & timeline, feel free to ask them.

Because I wrote a massive clusterfuck this chapter. Honestly think this was a badly written chapter (probably cause it was rushed).

Also, I'm going to use "Sabito" and "Zaiaku-kan" interchangeably during the BATTLE. So watch out for that.