Crossover: The Problematic Deity of Arcadia

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Mount Fujikasane – By the Stream

"Urgh!!"

Makomo dropped to her knees on the riverbed, clutching her throat as wave after wave of dry heaves racked her body.

Beside her, Shinobu Kocho knelt calmly, her voice as light as ever. "You okay over there?"

"I-I'm fine…"

Makomo forced the nausea down, not daring to look behind her. Her voice trembled as she asked, "Is it... over?"

"You mean Mr. Ryo's side?"

Shinobu, also avoiding any glance backward, dabbed the cold sweat from her forehead with a strained smile.

"Probably another twenty minutes to go. That'll make two hours, right?"

She looked toward Makomo, concern slipping into her tone.

"Want me to mix up a fast-acting herbal remedy?"

"No need…"

Makomo exhaled deeply, her face pale. These past two hours had squeezed out every drop of stomach acid she had. She wasn't sure she had anything left to vomit.

At that moment, from behind them came Ryo's calm, slightly disappointed voice.

"All the Healing Arts I know couldn't fix the damage? Shame. We were so close—just twenty more minutes."

Lying in front of him, the demon known as Hand Demon was a horrific sight: body mangled into a bloody mosaic, skull split open, face locked in despair. His bulging eyes were lifeless, drool pooling beneath him as he slurred:

"Kill me… You demon.... Please, just kill me already... Mom… Dad… Grandpa... Sis… anyone, please, make it stop..."

Ryo, adjusting his glasses, peeled off a pair of blood-soaked gloves. Shaking his head, he murmured:

"His soul's already shattered. He won't even reincarnate peacefully."

"What a waste. I've worked on a lot of experiments with Aizen, but my healing arts are still nowhere near his. If I were better, you might've made it through the two hours."

The Hand Demon only repeated his desperate, broken pleas. "Kill me."

Ryo let out a small sigh.

"Makomo, finish it."

At those words, Makomo snapped to her feet, responding instinctively: "Yes, sir!"

She turned, drew her Nichirin Blade, and without allowing herself to look at the ruined corpse, cleanly decapitated the demon.

In his final moments, the Hand Demon regained just enough clarity to smile through the tears, his voice ragged as he whispered: "Thank you… and… I'm sorry…"

Makomo froze for a moment, startled—but before she could ask anything, his body disintegrated into nothingness.

Shinobu waited until every last particle had faded from sight before finally turning around. Forcing a gentle smile, she looked to Ryo. "Mr. Ryo… did you discover anything?"

"Plenty."

Ryo packed away his tools into a [Gift Card], then lined up several glass vials on a rock beside the stream.

"This one holds neural tissue from the Hand Demon under control… this is mutated blood after demonization… here we've got cells with foreign genetic material, and…"

He gestured to the final vial, which shimmered dark red in the light.

"This one might contain Muzan Kibutsuji's blood."

The air went still.

Makomo and Shinobu both stared at the vial, eyes brimming with hostility.

Ryo, meanwhile, continued talking to himself.

"Who knew demons could be so… 'scientific'? Turns out Muzan uses electrical signals from brain cells and unique blood compositions to control his demons and place 'curses' on them."

"No mysterious powers. No unknown energies. Just an intricate biological structure buried in the blood."

He shook his head. "If Aizen were here, he could probably extract something more useful. My pharmacology's way too basic—I can only use what I understand."

Shinobu didn't ask who this "Aizen" was, nor did she question how Ryo's so-called "basic pharmacology" had unearthed secrets the Demon Slayer Corps had missed for centuries.

Her gaze lingered on the vials, voice trembling with anticipation.

"And what… exactly can we do with these?"

"What can we do?" Ryo smiled, lips curling into something between curiosity and mischief.

"With these, we could bypass Muzan entirely and control demons directly."

"We could even break the curses he places on them."

He looked toward her meaningfully.

"And if you're well-versed in curses… you might even track Muzan's exact location—or kill him remotely using his own blood as a conduit."

Shinobu's breathing quickened. "How… how would we do that?"

Ryo glanced at her, eyes twinkling. "Getting impatient, are we?"

She took a few deep breaths, steadying her emotions. Then, with a straight face and determined voice, asked:

"What do I have to give you in return?"

"Smart girl."

Ryo chuckled, stepping closer. "For now? Just stick with me."

"I'll wrap this all up within the month."

Shinobu's heart skipped a beat, but she quickly masked it behind a calm, lovely smile.

"Understood."

Satisfied, Ryo gave her a light pat on the shoulder, then turned to Makomo.

"And what about you, Makomo? The mountain's cleared—besides the Hand Demon, the rest have already been taken care of. The trial's over. What's your next move?"

Makomo wiped her mouth, then looked up at him, eyes steady. "I'm coming with you. To hunt demons."

"Interesting," Ryo smirked.

"Just so you know—my way of killing demons might not be what you're expecting."

"That's fine." She shook her head firmly, not a shred of hesitation in her voice.

At this point in her life, the only things that truly mattered to her were her teacher, Sakonji Urokodaki, and eradicating demons. Everyone else she'd ever loved was already gone—slaughtered by demons long ago.

Honestly, it wouldn't be wrong to say she had no one left.

Calmly, she added: "Could I get a piece of paper? I want to write a letter to my master."

"Ask the Demon Slayer Corps when we're down the mountain."

---

Base of Mount Fujikasane

At the foot of the mountain, the Demon Slayer Corps support squad—known as the Kakushi—stood by in formation. Beside them were the children of the Head of the Ubuyashiki family, Kiriya and Kanata.

Kanata, dressed in a black kimono with a sakura pattern, white hair fluttering, gazed up at the sky. "Onii-sama, the rain has stopped."

Kiriya, wearing a similar outfit but with black hair, spoke with quiet sorrow.

"I just hope fewer of the recruits died in this selection round…"

Kanata closed her eyes, voice soft. "Let's hope so."

Suddenly, the sky was filled with the piercing cries of crows. One swooped down, shrieking in an almost human voice:

"Message from the Master! Message from the Master!"

"To my children, Kiriya and Kanata—should the Final Selection end early due to unforeseen circumstances, assist Slayer Shinobu Kocho in welcoming a distinguished guest by the name of Lord Ryo Yagami."

"Black hair, black eyes, wearing an all-white custom uniform. Striking appearance and a unique presence. Show him the utmost respect."

"If he is willing to meet with me, please invite him to Butterfly Mansion."

The siblings looked at each other, startled.

"Father's orders… What's going on up there?"

"No idea. But let's just follow the instructions."

At that moment—

Amidst the swaying fields of wisteria at the mountain's edge, a young man in white descended the steps, flanked by two women.

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.

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