The magic circle flared crimson, runes spinning once before snapping into place.
When the light faded, the four of them stood inside Gremory territory.
Kunou's ears twitched first. She looked around slowly, tails swaying.
"The nature energy is strong here."
Nate took a breath.
He felt it too.
Not wild. Not chaotic.
Controlled. Cultivated.
"Yeah," he said, a little surprised. "Like the peak parts of Kyoto."
Tall trees surrounded the clearing, their roots thick and old, mana flowing through the soil like veins. The air itself felt maintained, as if the land had been shaped over generations rather than conquered.
Nate nodded once. "Makes sense."
Grayfia stepped forward without another word, already moving toward the only structure in sight.
A massive mansion, elegant and ancient, standing proudly at the heart of the territory. The Gremory crest was carved above the doors, subtle but unmistakable.
Serafall floated beside Nate, hands behind her back, humming cheerfully.
Kunou followed close to Nate, both of them carrying their bags as they walked.
Nate's eyes stayed on the mansion.
'So this is it.'
He exhaled slowly.
'DxD main cast. Devil politics. Rating games. Peerages.'
His lips curled slightly.
'And they just invited the Yokai King into the middle of it.'
They reached the front steps.
Grayfia stopped and turned to him.
"Please mind your words inside," she said calmly. "Many eyes will be watching."
Nate met her gaze and gave a respectful nod.
"Understood."
Then he looked at the door.
'Alright.'
'Let's see how this world reacts to me.'
The mansion doors opened.
And the ten days began.
Serafall stepped into the mansion first, hands cupped around her mouth like she owned the place.
"Rias-chaaan~! We're here!"
Footsteps echoed down the stairs.
Rias Gremory appeared a moment later, long crimson hair flowing down her back, posture elegant as ever. She smiled warmly when she saw Serafall.
"Serafall-sama, welcome—"
She stopped.
Her eyes shifted.
Locked.
On him.
Nate raised a hand and gave a casual wave. "Yo."
The air changed.
Rias felt it instantly.
Heavy. Vast. Calm.
Power that didn't flare or threaten—
it existed, like gravity.
'Satan-class…?'
No.
'No, this feels different.'
Her magic circuits screamed warnings, instincts flaring hard enough that she had to steady herself on the railing.
'That's not devil power.'
Her gaze sharpened, scanning him properly now.
Young.
Too young.
Brown hair. Calm eyes. Relaxed posture. No fear. No tension.
'Brother said he was sixteen.'
Her brain stalled.
'Brother did not lie. He really is sixteen.'
She descended the stairs slowly, eyes never leaving Nate.
Kunou felt it and stepped half a pace closer to him, tails swaying protectively.
Grayfia watched silently, already cataloging reactions.
Rias stopped a few steps away.
"…Serafall-sama," she said carefully, "who is this?"
Serafall beamed.
"This is Nate Adam. The Yokai King. Z-rank. Satan Class."
Rias's composure cracked.
"…The what?"
Nate scratched the back of his head. "Hi. You must be Rias."
Her eyes snapped back to him.
He bowed—not deeply, but respectfully. Perfectly balanced.
"Nice territory. You take good care of it."
That did it.
Rias's face went blank for half a second.
'He's complimenting my land.'
'Why does that feel like approval?'
'Why does that matter?'
She straightened immediately, pride flaring. "Th-thank you."
Then she frowned.
"…Wait."
She narrowed her eyes.
"You're the Yokai King."
"Yeah."
"And you're here to—"
"Train your peerage," Nate finished. "If you want."
Her heart skipped.
Not arrogance.
Not obligation.
A choice.
She looked past him, at Serafall.
"This… is who you meant?"
Serafall nodded happily. "Yup~"
Rias turned back to Nate.
Studied him again.
'Calm. Confident. Ridiculous power.'
'And he doesn't look down on me.'
Her lips curved into a smile—sharp, competitive.
"Then," she said, "I look forward to working with you."
Nate smiled back, just as sharp.
"Same."
Somewhere deep in the mansion—
Sirzechs sneezed.
And Rias had no idea her entire ten days were about to rewrite her understanding of power.
Nate looked back at Rias. "So… your peerage?"
Rias nodded and turned. "Everyone, come in."
Footsteps echoed.
They entered together.
Exactly who Nate expected.
Akeno stood relaxed, a teasing smile already on her lips, lightning aura faint but unmistakable.
Kiba stood straight, knightly and polite.
Asia smiled warmly, hands clasped.
Issei scratched his head, clearly still processing everything about life.
Koneko stayed quiet, eyes sharp and observant.
Then—
Nate's brain slammed into a wall.
She stood there, arms crossed, expression sour.
Black hair. Fallen Angel wings long gone. Devil aura unmistakable.
Raynare.
Nate blinked.
Once.
Twice.
Five times.
'The fuck.'
'She should be dead.'
'No, not dead—dust. Erased. Void food.'
His gaze locked on her.
'How is she alive?'
'Why is she alive?'
'Why is she a devil?'
Rias noticed instantly. "Is everything okay?"
Nate slowly shook his head. "No."
Everyone tensed slightly.
He exhaled. "Didn't expect to see a Fallen Angel who murdered the Red Dragon Emperor candidate… alive. And definitely didn't expect her to be a devil."
Raynare clicked her tongue, looking away. "Tch. Like I wanted this."
Rias stepped forward. "I should explain."
She did.
Cleanly. Directly.
No drama. Just facts.
Raynare killed Issei.
Rias reincarnated him.
Asia was nearly killed.
The peerage arrived in time.
The Fallen Angels were defeated.
[Insert image is alll the character here]
And when they caught Raynare—
Issei told Rias to end it.
Silence followed that part.
Sona intervened.
Azazel was called.
And Azazel, in his infinite Azazel logic, decided punishment didn't need execution.
Instead—
Raynare was stripped of her Fallen Angel status.
Reforged.
Bound.
Rias Gremory's second Rook.
When Rias finished, the room stayed quiet.
Nate nodded slowly.
On the outside? Calm.
Inside?
'Oh this is absolutely because I exist.'
'Canon already tripped, fell down the stairs, and broke its neck.'
He glanced at Issei.
Issei met his eyes, awkward. "Uh… hi?"
Nate studied him for a second, then nodded. "You're alive. That's already a win."
Issei laughed nervously. "Y-Yeah?"
Nate looked back at Raynare.
She met his gaze this time.
No smugness.
No arrogance.
Just resentment and something close to exhaustion.
"…You hate me," she said flatly.
Nate tilted his head. "I don't hate you."
That surprised her.
"I just don't trust you," he continued. "Yet."
Rias stiffened slightly.
Nate turned to her. "But you didn't erase her."
"Yes," Rias said quietly.
"That was a risk," Nate said. No accusation. Just fact.
Rias met his eyes evenly. "So is asking you to train us."
A pause.
Then Nate smiled.
Not soft.
Not cruel.
Interested.
"Good," he said. "I don't do boring."
Raynare frowned. "Tch. Figures."
Kunou's tails swayed behind him, amused.
Grayfia observed silently, eyes narrowed in thought.
Nate clapped his hands once.
"Alright," he said. "Ten days. No holding back. No shortcuts."
His gaze swept the peerage.
"And by the end of this—"
He smiled wider.
"Raiser's gonna regret having feathers."
Somewhere very far away—
A phoenix sneezed.
And didn't know why.
Everyone was outside in the courtyard.
Everyone was looking at Nate.
Nate looked at everyone. "I will be honest with all of you, outside of Akeno and Rias who are SS and A, the rest of you are B and barely A".
Issei blinked. "What's with the letter"
Grayfia answer. "The Yokai use a different rank of power, E → C for Low Class,
B for Middle Class,
A → SS for High Class,
SSS → Z for Ultimate Class,
ZZ → UZ for Satan Class,
and finally, UZ+ for Superclass".
Nate pointed at him self. "I am z
ZZ, and Kunou is also Z".
Silence.
Not the awkward kind.
The existential kind.
Issei stared at Nate like his brain had blue-screened.
"B–barely A…?" he repeated. "I'm… barely A?"
Koneko's ears twitched. "…Tch."
Kiba frowned, but kept his composure. "Middle Class… by Yokai standards?"
Asia clasped her hands nervously. "I–I'm B…?"
Akeno, meanwhile, smiled sweetly.
"Oh my~ I'm SS?" she asked, tilting her head. "How flattering."
Rias didn't smile.
She was staring at Nate with narrowed eyes, crimson aura slowly leaking out.
"Explain," she said calmly.
Which was infinitely more terrifying than if she'd yelled.
Grayfia adjusted her glasses, already realizing the political implications.
"ZZ… Satan Class by Yokai standards…"
She glanced at Nate again. "…That places you above most Devils."
Sona crossed her arms. "That ranking system is… extreme."
Nate shrugged. "Different fraction, different baselines. Devils measure potential. Yokai measure threat."
That did not help.
Kunou, who had been happily munching on snacks nearby, raised her hand.
"Kunou is Z! Nate said I'm strong!"
Everyone slowly turned.
Rias felt her soul leave her body.
"…Your friend," she said carefully, "is Ultimate Class?"
Nate nodded. "Yeah. Still growing, though."
Issei dropped to his knees.
"I just got reincarnated," he muttered. "Why is life already bullying me?"
Rayner scoffed. "Great. I die once, get resurrected, and now I'm B-rank fodder."
Nate glanced at her. "You're lucky. In Yokai terms, Fallen Angels cap early."
Rayner: "—Wow. I hate you."
Akeno laughed. "Ara ara~ How cruel."
Rias pinched the bridge of her nose.
"So let me get this straight," she said.
"You're Satan Class. My peerage is mostly Middle Class. And you just… walked in."
Nate nodded again. "More or less."
Her eyes sharpened.
"And you're sixteen."
Nate winced. "…Yeah, about that—"
CRACK.
Rias's demonic power flared for half a second before she forcefully suppressed it.
Akeno leaned in and whispered, delighted,
"Oh my~ Rias, you look like you're about to short-circuit."
Rias snapped back instantly.
"I am perfectly calm."
Grayfia deadpanned.
"You are emitting enough magical pressure to trigger a territorial response."
"…I am adjusting."
Nate rubbed the back of his neck.
"Look, if it helps, I'm not here to flex. Rankings are just… context."
Sona studied him carefully.
"And if you were hostile?"
Nate met her gaze. Calm. Honest.
"This city wouldn't exist."
That did it.
Everyone felt it then—not his power flaring, not pressure—
—but certainty.
Issei swallowed. "…So what do we do now?"
Nate smiled.
"Now?"
"We talk". 'Because DxD canon already went off the rails, and it's probably my fault.'
Inside his head, Nate sighed.
'Yep. Definitely my fault.'
Kiba raised his hand. "I can't believe an 11-year-old is a High Ultimate Class".
Nate blinked as he realised. "She is 16, Kunou, true form".
Kunou snapped her finger as she transformed back to her 16 year-old self
Kiba froze mid-sentence.
Everyone did.
Kunou snapped her fingers.
Golden light rippled outward, foxfire curling around her like silk. Her small frame stretched, posture straightening, aura expanding—not violently, but royally. When the light faded, a sixteen-year-old Kunou stood there: taller, sharper eyes, her presence suddenly matching the weight she carried. She now had a curvy figure with a Cub size similar to Rias
Nine tails fanned out behind her slowly.
The courtyard went dead silent.
Issei stared. "…Oh."
Koneko's jaw dropped a fraction.
"…She got taller."
Akeno's smile widened, dangerous and delighted.
"Oh my~ so that's your true form."
Rias felt her demonic power instinctively flare—then immediately retreat.
That aura wasn't just strong.
It was ancient.
Kunou crossed her arms proudly and leaned slightly into Nate's side.
"I told you I wasn't a child."
Nate nodded. "Yeah, that one's on me. I forget people don't default to 'fox spirit rules.'"
Kiba cleared his throat, trying to regain composure.
"S–So… she's sixteen. And Z-rank."
"Yes," Nate said calmly.
Grayfia added, deadpan,
"And his fiancée."
That did it.
Rias's brain hard rebooted.
"…Fiancée."
Issei whipped his head back and forth between them.
"WAIT—WHAT?!"
Kunou smiled sweetly, tails swaying.
"We're engaged. Politically and romantically."
Akeno covered her mouth.
"Oh my~ starting young and efficient."
Rayner groaned. "Of course the Yokai King has a High Ultimate Class fiancée. Why wouldn't he."
Rias finally found her voice.
"…You're engaged. To a Z-rank Yokai. Who is also—"
She paused, recalculating everything she thought she knew about power, politics, and reality.
"—part of a prophecy."
Kunou tilted her head.
"Child of Prophecy, actually."
Sona muttered, "…This is worse than I thought."
Nate shrugged again.
"Look, if it helps, Kunou's holding back. A lot."
Kunou puffed her cheeks.
"I am!"
Grayfia closed her eyes briefly.
"So this is the individual Sirzechs wants training Rias' peerage."
Rias looked at Nate again—really looked this time.
Not just his power.
His confidence. His ease. The way he stood beside Kunou like this was normal.
"…Brother didn't undersell you," she admitted quietly.
Nate smiled.
"He usually doesn't."
Inside his head, Nate sighed.
'Yep. DxD canon is officially dead.'
And honestly?
He was having fun.
Nate pulled out a Yokai Medal, the metal gleaming softly in the sunlight.
He slid it into his watch.
Click.
"Yo-kai… Watch!"
Blue light burst out as a familiar floating figure appeared, bow tie straight, tablet already in hand.
"Behold!" Whisper announced proudly. "The one, the only—your ever-reliable Yokai butler, Whisper, at your service faster than Nate can get adopted by another supernatural faction!"
Nate ignored that and held out his hand.
Whisper immediately floated over and handed him the tablet.
"Everything has been planned out in advance, sir."
Nate scrolled through it, eyes narrowing slightly—not in worry, but focus.
"Sirzechs gave me full access," Nate said calmly. "Strengths. Weaknesses. Gear limitations. Bad habits. Emotional triggers." He glanced up at the peerage. "I'll tailor your training around all of it."
Issei raised a hand slowly.
"Uh… what if someone steals that?"
Whisper laughed, clutching his nonexistent stomach.
"Oh-ho-ho! Impossible!"
He floated closer to Issei, tablet glowing faintly.
"The tablet is locked behind a Rhythm-Based Password System," Whisper said proudly. "One must input the correct melody, tempo, and emotional intent using spiritual energy."
He leaned in.
"And even if you somehow guess the notes—"
The screen flashed red.
"—you'll still need Nate's spiritual signature."
Issei blinked.
"…So basically it's impossible."
"Correct!" Whisper beamed.
Rias crossed her arms, studying the tablet with a serious expression.
"You already prepared all of this?"
Nate nodded.
"I don't like wasting time. We have ten days. Riser has experience, endurance, and phoenix regeneration." His eyes sharpened. "So we're not playing catch-up. We're breaking limits."
Kunou stepped forward, tails swaying.
"And we're not training everyone the same."
Nate smiled.
"Exactly."
He tapped the tablet, projecting several glowing panels into the air.
"Kiba," Nate said, pointing. "You rely too much on speed. We're fixing your stamina and counter-pressure."
Kiba straightened. "Yes!"
"Asia," Nate continued gently. "You're a support powerhouse, but you hesitate. We're fixing that confidence."
Asia nodded, nervous but determined. "I-I'll do my best!"
"Issei." Nate looked at him directly.
Issei swallowed.
"You've got insane potential," Nate said flatly. "But zero discipline. We're drilling control before power. No boosts until you earn them."
Issei sighed. "…Figures."
Akeno tilted her head, smiling.
"And what about me~?"
Nate met her gaze without flinching.
"You enjoy chaos too much. I'm giving you structure."
Akeno's smile widened.
"Oh~ I like you already."
Rias took a breath.
"And me?"
Nate paused, then spoke honestly.
"You're strong. Talented. But you fight like a leader who's afraid of losing people." He met her eyes. "I'm going to teach you how to fight like a king."
The courtyard went quiet.
Rias nodded slowly.
"…Understood."
Whisper cleared his throat.
"Training begins at dawn tomorrow! Expect pain, growth, screaming, and at least one existential crisis!"
Issei groaned.
"Why do I feel like I'm gonna die?"
Nate smirked.
"Relax. I won't let you die."
He paused, then added casually—
"Lose consciousness? Probably."
Kunou laughed.
'This is gonna be fun', Nate thought.
'And Ophis is going to love the chaos.'
To be continued