Akira and Tengen leapt down the tunnel the Hashira had dug. Tengen could've easily used his Sound Breathing to do it faster, but they didn't want to attract any attention from the demon just yet.
They landed lightly in the underground chamber. The space was vast, the air damp and heavy. magenta-colored obi with eerie human-like patterns hung from the walls like tapestries of flesh. Human bones lay scattered across the ground.
Akira's eyes glowed faintly. "This demon must've used this as a storage room, where it keeps humans it's captured to feed on later."
Tengen frowned, studying the writhing sashes. "And those patterns… those are people, aren't they?"
"Yes," Akira replied grimly. "They're real humans. Sealed within the obi."
Suddenly, a woman's voice echoed through the chamber, cold and venomous.
"What do you think you're doing? How dare you intrude on someone else's food locker! I'll make sure you both regret it!"
They turned toward the source, and one of the obi slithered forward, its edge splitting into a grotesque mouth and blinking eyes.
Akira raised an eyebrow. "Well, that's… a weird demon."
Tengen sighed. "Happens more often than you'd think. Anyway, we need to figure out how to free them."
"That's relatively easy," Akira said, analyzing the writhing sashes. "Just cut through the obi, but don't slice through the parts with human patterns."
"Sounds simple enough," Tengen replied.
The obi demon screamed in rage, "How dare you ignore me! I'll make you both suffer before I eat you!"
Akira and Tengen continued talking casually, completely ignoring her.
"Oh, did you find your wives?" Akira asked conversationally.
"Yes," Tengen said, scanning the hanging sashes. "I can see all three of them here… and Zenitsu's here too."
"Good. Then are you ready?" Akira asked, reaching into his inventory. The massive, huge blade, the Demon Slayer Sword, emerged with a metallic hum.
Tengen twirled his dual blades and smirked. "Always."
Both men moved at the same moment. Their forms blurred, cutting through the air faster than the eye could follow.
The obi demon froze. "How are they moving so fast?! Forget about the dual-wielding one, but that huge sword-wielding guy, but how can he move like that while carrying that monster of a weapon?! And where did he even pull it from?!"
Before she could collect her thoughts, both slayers were already slicing through her body with blinding speed.
Tengen laughed mid-fight. "That's a flamboyant sword you've got there! Didn't think you could move so fast with it!"
Akira grinned, swinging the giant blade effortlessly. "Yeah, it's cool, but harder to wield than I thought. A bit exhausting though."
The demon stared in disbelief. "They're talking… in the middle of battle? Like nothing's happening?!"
She lashed out repeatedly, but their attacks were relentless. In moments, more humans were freed from her bindings.
Then, suddenly.
"Thunder Breathing, First Form: Thunderclap and Flash!"
Then something tore through the demon's boy as it split apart, before it could even react.
"Sixfold!" Zenitsu's voice rang out as he blurred past, cutting through the obi faster than sight.
In a flurry of flashes, the obi slashes were severed, the bindings falling limp. The humans sealed inside began to collapse to the floor, freed at last.
The demon's panic spiked. "No! I'll be destroyed if I stay here. I have to get back to Daki-sama!"
With desperate rage, she flung her remaining obi toward the helpless people still lying on the ground.
Akira, Tengen, and Zenitsu moved instantly, slashing through the attacking obi slashes, protecting the freed captives.
When the last obi fell, Akira exhaled. "She escaped."
Tengen nodded grimly. "Yeah… she used part of herself as a diversion."
Before they could regroup, a weak voice called out, "Tengen-sama!"
They turned to see three women, Tengen's wives, standing a short distance away. One of them looked pale and barely conscious, her body trembling.
Tengen rushed over immediately. "What happened?"
One of the wives spoke, tears in her eyes. "Tengen-sama, she… I think she poisoned herself."
The weakened woman coughed, her voice faint. "Tengen-sama…"
Tengen knelt down quickly, pulling a small medicine pill from his belt and slipping it into her mouth.
"Don't speak," he said firmly.
But she continued anyway. "Forgive me, Tengen-sama… I realized that Warabihime Oiran was a demon… but she grew suspicious of me. So I drank poison to fake my death and tried to escape… but her belt captured me before I could escape."
Before anyone could say more, a loud crash echoed from above, the sound of destruction shaking the entire chamber.
Akira looked up toward the source, his expression hardening. "Seems like things are getting serious up there." He glanced back at Tengen. "Take care of them. I'll go ahead."
Before Tengen could respond, Akira stored his massive sword back into his inventory and leapt upward through the tunnel they had entered from.
Zenitsu followed soon after, still asleep, yet somehow keeping up.
Akira hoped the situation above hadn't escalated too far.
Meanwhile, as Akira and Tengen descended into the underground chamber, at the very same time, Tanjiro, Inosuke, and Erika were moving toward their target, the Upper Moon demon.
They soon found themselves standing atop a rooftop, facing a window glowing faintly in the night.
Erika pointed ahead. "The demon should be in that room."
Tanjiro sniffed the air, his expression firm. "Yes. The scent is strong, there's no mistake."
"Heh-heh!" Inosuke grinned beneath his boar mask. "Then I'll start!"
Before anyone could stop him, he charged forward.
"Wait! There might be people in there!" Tanjiro shouted, leaping after him, but it was already too late.
Inosuke smashed through the window in a single bound. A moment later, a violent impact echoed as something slammed outward.
Inosuke came flying back through the air, crashing straight into Tanjiro. Then both of them crashed into a nearby building with a resounding sound.
Erika blinked in surprise. "What the…?"
From the shattered window, a woman emerged, no, a demon.
She was breathtakingly beautiful, her skin pale as porcelain. Her long black hair was tied into a high ponytail, its ends dyed a soft green that shimmered under the lantern light. She wore only black-magenta undergarments, her magenta obi sash swirling around her body like living serpents, floating as though they had a will of their own.
Etched into her irises were the words Upper Rank and Six, the same markings Erika had seen before on the Upper Rank Three.
"So you're Demon Slayers?" she asked, voice dripping with arrogance. "How many of you are here? Is there a Hashira among you?"
Erika's gaze sharpened as she noticed something, one of Daki's obi contained a woman's upper body protruding from the fabric, the rest of her seemingly absorbed within the sash.
"What… what did you do to her?" Erika demanded.
Daki turned her head, finally noticing Erika. Her lips curved into a hungry smile.
"Oh, you're beautiful," she purred. "I'll enjoy eating you. As for what I'm doing to her, I'm storing her for later. I don't eat dirty old people or anyone ugly, so I keep the ones worth savoring."
Erika's eyes narrowed, anger flickering behind her calm expression.
"Release her," Erika ordered coldly.
Daki's expression immediately twisted with anger. "How dare you talk to me like that!"
Two of her obi slashes whipped forward like serpents, cutting through the air toward Erika.
But Erika didn't flinch. Instead, she raised her hands and called out,
"Serve me — Églantine!"
In a flash of red light, two crimson ribbons appeared, binding themselves to her arms and extending outward with a life of their own. The ribbons met Daki's obi mid-air, blocking them with a resounding crack! as sparks of energy scattered between them.
Daki blinked in surprise. "Oh? What's this? Something I've never seen before." Her eyes narrowed, studying Erika carefully. "And you… You feel different. Are you even human?"
Erika glared. "I'm more human than you." Her ribbons began to glow as her breathing shifted. "Blood Breathing, First Form — Crimson Throne Prison!"
The crimson ribbons shot forward, spiraling and coiling around Daki, trying to bind and crush her. Daki reacted instantly, her floating obi slashing out to block the attack.
"I'll eat you and find out what you are!" she sneered, but then froze.
Her eyes widened as the air around her began to distort, the floor beneath her cracking under a sudden spike of gravity. Erika's ribbons glowed brighter, infused with her gravity magic, and began to overpower Daki's obi.
"N-not bad," Daki hissed, her smile fading into frustration. "You're strong!"
At that exact moment, Tanjiro and Inosuke recovered from their earlier fall and charged in from both sides.
"Now!" Tanjiro shouted.
"I'll rip you apart!" Inosuke roared, his twin blades flashing.
Daki smirked. Her obi slashes struck the ground, and her form blurred.
She disappeared, reappearing on a nearby rooftop, looking down at them with disdain.
"Unfortunately for you," she said, her tone dripping with arrogance, "all of you are far too weak to face me."
Behind her, the woman who had been trapped in Daki's obi finally lost her form completely, her body sinking into the sash, her shape flattening until it became nothing but a part of the fabric's pattern.
Erika's eyes widened, and Selena's voice echoed in her mind. "Erika-chan, the woman trapped in her obi, to free her, you have to cut it carefully without slicing through the human pattern. That's the only way to free her."
"Got it," Erika replied silently, tightening her grip.
Her ribbons flared crimson. "Cut her obi and release that woman!" she shouted, launching another attack.
Her ribbons shot forward once more, crashing against Daki's spinning obi. Tanjiro and Inosuke joined the assault.
"Release those women!" Tanjiro shouted.
"You're not getting away!" Inosuke roared.
Their blades clashed mid-air, sparks and silk filling the sky.
Daki deflected every strike with contemptuous ease. Her obi danced like living steel, blocking and countering faster than their eyes could follow.
Tanjiro gritted his teeth, switching forms. Sun Breathing!
His blade flared as he slashed through one of the obi, freeing the woman's pattern from it.
But before he could react, Daki retaliated, her sash slamming into both him and Inosuke, sending them crashing into the ground once again.
Landing gracefully atop another roof, Daki smiled cruelly. "Not bad. You even managed to separate the one I'd trapped… Koinatsu, wasn't it?"
Erika's ribbons shot forward again, lashing toward Daki like living whips. But this time, the demon blocked effortlessly, her obi slashes moved faster, denser, more aggressive.
Even Tanjiro's Sun Breathing wasn't enough to break through her defense. The obi protected her from every angle, deflecting all three of their attacks like an impenetrable shield.
Then suddenly, something new streaked through the air.
Before they could regroup, a new obi flew through the air, impaling Daki's neck before merging into her body.
Erika, Tanjiro, and Inosuke froze.
"What… what is that?" Erika muttered.
Before they could move, Daki leaped backward, landing on a rooftop. Her hair began to glow, shifting from black to pure white. Her aura surged violently.
She opened her eyes, smiling with twisted delight. "So the Hashiras have arrived after all. Two of them, even? How wonderful. My master will be pleased."
Then, suddenly, a furious voice cut through the chaos.
"You guys need to shut the hell up!"
Everyone turned, and they saw a man had stormed out of a nearby house, red-faced with anger. "What's the deal with that sword?! You've got a lot of nerve brawling in front of my house! What kind of harassment is this?!"
Erika blinked in disbelief as more people began to emerge, drawn by the commotion.
The man continued, "I'll have you know this district only thrives because we and our clients follow the rules! People like you aren't welcome here! Get out of my sight!"
Daki's expression darkened. "Why don't you shut your mouth?"
Her obi shot outward, dozens of them slicing through the air.
"Don't come close! Go back!" Tanjiro shouted, rushing to protect the man.
Inosuke and Erika lunged forward again, but there were too many.
Daki raised her hand and with a single motion, every one of her obi slashed outward in all directions.
A flash of magenta light tore through the night.
Then the world seemed to pause, and then every nearby building around them was sliced apart in an instant.