Among demons, there were those like Akaza, Daki, and Gyutaro—people who died under the weight of misfortune and became demons. No matter how tragic their human lives were, it didn't absolve them of the crimes they committed after, but their stories could still make one feel a hint of pity.
But alongside Akaza and his ilk, there were also demons who had already piled up countless sins even before turning—villains who deserved to die a thousand deaths.
Kaigaku, for one. And the Hantengu before her now.
Kaigaku had once been one of the orphans taken in by the Stone Hashira, Himejima Gyomei. He was driven out after repeated thefts from the others, ultimately bringing disaster: to escape a man-eating demon, Kaigaku extinguished the wisteria incense that protected the temple, allowing the demon to slaughter Gyomei's children and leaving Gyomei himself wrongly accused of murder and nearly executed.
Later, Kaigaku fled to Mt. Sagiri and became a disciple of the former Thunder Hashira, Kuwajima Jigorou, making him Zenitsu's senior. But during a mission, he encountered Upper Moon One, Kokushibou. Terrified, he accepted demon blood and turned into a demon. When Kuwajima learned his student had fallen, he blamed himself and took his own life.
If it had been just a matter of wanting to live, Nightingale might have understood—fear of death is only human. What she despised most about Kaigaku was that, after hearing of his master's suicide, he felt not an ounce of remorse or grief; he blamed everything on Zenitsu, insisting Kuwajima had always favored the latter and never truly taught him, so his death was deserved. Even animals know gratitude, but Kaigaku… not even that.
But the Upper Moon she despised most, aside from Kaigaku, was Hantengu.
Even as a human, Hantengu was a criminal—and not even one who knew his own guilt.
When rice was being distributed to the blind and destitute, Hantengu disguised himself to get handouts. Instead of being grateful, he stole from those who helped him. When another blind man tried to report him, Hantengu killed him in panic. He tried to feign blindness to escape punishment, but was seen through and sentenced to death. On the eve of his execution, Kibutsuji Muzan turned him into a demon, and Hantengu immediately slaughtered the magistrate.
"It wasn't me who stole; it was my hands. I didn't kill anyone; I was forced to by others…" Over and over, he coated his sins in lies.
Hantengu, master of deceit, truly believed he'd never told a lie since birth, saw himself as a pitiful, blameless weakling, and could not fathom why the world never showed him any sympathy.
Such twisted, repulsive ugliness!
Kokushibou, Gyokko, Dōma—they too had committed unforgivable evils. But Hantengu and Kaigaku's actions filled Nightingale with a deeper disgust.
"In this world, physical pain is certainly terrible… but it seems that spiritual sickness can be even harder to endure."
Despite her slender frame, an overwhelming aura surged from Nightingale—enough to still a raging storm. She stared at Hantengu, her eyes shining like blood.
"E-eeeek?!"
That sharp gaze made Hantengu wail, burying his head even lower and covering his eyes, desperate not to meet those crimson eyes.
"Why… Why do you all bully a weak old man like me…? Why do I always have such terrible luck…? Why must I always meet such heartless monsters…?"
Utterly twisted, Hantengu saw none of his own evil, only railing against fate, hating others for no reason, never taking responsibility.
For once, Nightingale's face showed open disgust.
Unwilling to listen to another word, she stomped the ground, claws forming from her bent fingers as she slashed through the air with a chilling gust.
CRACK!
A massive tree was cleaved in two, splinters flying. Deep furrows split the earth.
"E-eeeeeeek!!"
Hantengu barely dodged the first blow, shrieking, but before he could catch his breath, Nightingale's kick shattered the air, barreling toward him.
In midair, Hantengu had nowhere to run.
The crushing kick landed squarely in his gut, translucent force tearing through him like a hurricane, scattering dust, snapping trees, and shaking the earth like thunder.
Even with a body tougher than stone, Hantengu met only one fate—he was torn to shreds, meat and viscera flying.
"Eeeeeek! S-So scary! I'm split in two! Cut right in half!"
His abdomen, flesh, and organs were crushed to pulp, his upper and lower halves separated. Such wounds would be fatal to any ordinary human—even someone like Satoru Gojo would die from that.
But for a demon with life force surpassing cockroaches, this was nothing.
At the severed points, flesh and bone regrew visibly fast. By the time Hantengu landed, his wounds had vanished—and now there were two of him.
"Heehee! Hahaha! This is great! I get to go wild again!"
One held a maple-shaped fan, the word "Pleasure" (Kokushō) on his tongue—Hantengu's clone, Sekido.
"What's there to be happy about? All I feel is endless rage. That woman attacking us, you, all of it infuriates me!"
The other, wielding a metal staff and the character for "Anger" (Sekido) on his tongue, was Hantengu's clone—Sekido.
"More patients to treat, I see?"
Nightingale swept her gaze over the two, her voice unwavering. "No matter. I'll press on until dawn, lantern in hand, tending every patient's wounds—no hardship will break me!"
"Hah! What nonsense are you spouting, woman?"
Sekido cackled sharply. "Are you putting on a play? That would be fun!"
"Enough, enough, enough… My rage burns, scorching my chest!"
Sekido's face twisted with fury. "Your voices, your faces… all of you piss me off! Just die already!"
He struck the ground with his staff.
A blinding flash of lightning split the night, a tree of lightning branching out and crashing toward Nightingale.
BOOM!
A massive thunderbolt slammed into her, scorching the earth black.
"Ha! Direct hit! My turn now!"
Pleasure charged, unafraid—he knew Sekido's lightning well, and didn't worry about the aftermath. There's no way a human could survive that.
But Sekido's face changed.
"Idiot! That woman—"
He didn't even finish. Not that it mattered.
Right before their eyes, the lightning was shattered. Nightingale, save for some smoke, was completely unharmed. She bore down on Pleasure with an overwhelming force, like a rampaging war chariot.
"Wha—?!"
Pleasure froze in his tracks, but Nightingale was already on him.
Every hair on his body stood on end—before her fist even fell, Pleasure felt his body and soul about to be pulverized.
"Fly—!"
Ignoring Pleasure's windstorm attack, Nightingale charged through it. From her perspective, it was less like wind and more like a solid wall slamming into her—a force that would have turned any normal person to paste.
Earth was torn up, stones whipped about like bullets in the gale.
"Dead yet? Ground to pieces? Trapped in a storm of shrapnel, torn apart bit by bit, screaming like a dying crow…"
Pleasure retreated, muttering, "That would make for a lovely story, wouldn't it? Entertaining…"
"Idiot! Where are you looking?!"
A roar from behind startled Pleasure.
Through the rift of storm and darkness, that flash of crimson was unmistakable.
The lightning roared, lashing toward Nightingale—a tremendous, destructive strike.
But Nightingale didn't even turn, only reached back with one hand.
RIP—
To Sekido's astonishment, she grabbed the very heart of the thunderstorm—and ripped it apart.
Just then, Pleasure turned back—only to see Nightingale's hand, still crackling with lightning, lancing straight for him.
CRACK!
The air screamed with a thousand birds' cry as her hand stabbed through Pleasure's eye, splitting his skull nearly in two.
She… stabbed through my head with her fingers? Who's the real demon here?
As Pleasure reeled, Nightingale frowned, clearly dissatisfied.
Then, without pause, she seized one of his horns with her other hand. Gripping tightly—
RIP—
She tore the demon clean in half.
Blood gushed, organs spilling in a torrent.
BOOM!
Thunder fell from the sky, but still could not harm Nightingale.
"Damn, damn, damn… Why isn't this working?!"
Sekido's rage only grew hotter.
He could never have guessed that his foe possessed [Magic Resistance C], a skill that could cut down magical damage. While C-rank resistance might mean little in a battle of Servants, it was more than enough to trivialize these demons' Blood Demon Arts, especially paired with Nightingale's B+ Endurance. Hurting her with lightning was as naive as trying to pierce Karna's armor with Hassan's dagger.
"Damn it! This miserable, unfair life… It makes me furious!"
Watching Nightingale advance, Sekido nearly ground his teeth to dust. "You—! You're a monster! You bully us weak, pitiful folks with such overwhelming strength! Don't you have any mercy? Don't you feel guilty?!"
Nightingale said nothing, her silence heavy as lead, expressing her own anger far better than words.
"Think you can ignore me and walk away, you bully? Don't think—"
Disgusted by Sekido's ugly tirade, Nightingale moved.
One moment, Sekido was standing; the next, his head was gone.
Behind him, Nightingale stood silently, holding his dripping head, those eyes still brimming with confusion.
He hadn't even seen her move or realized what happened—his head had been ripped away, and even the pain lagged behind.
"You—!"
Sekido tried to howl, but Nightingale wasn't interested. With a flex of her hand, she crushed his head to pulp, red and white splattering everywhere.
Then she turned to the remaining three demons, now hesitant and afraid.
"Which of you is next to receive treatment?"
Besides the rapidly regenerating Pleasure, two more—Sorrow (Aizetsu) and Joy (Urogi), Hantengu's other clones.
"So tragic, so sorrowful…"
Aizetsu, wielding a cross-shaped spear, spoke up. "Power blinds you, and so you can't see your own death."
"I delight in this fated victory."
Urogi, with his bird wings and talons, laughed. "You can't kill us. Even if you chop off our heads with a Nichirin Blade, it's useless. We can revive and split endlessly. But you—how long can your stamina last?"
"I'm guessing you've killed your fair share of demons before, which is why you're so proud of yourself."
Pleasure's eyes locked on Nightingale. "But we're different from any demon you've faced before. Even if you decapitate us with a Nichirin Blade, you can't kill us. Only Sun Breathing can destroy us. Unless you or your friends have a Sun Breathing user, you're all doomed tonight!"