"Humaaan, humaaan, are you done wiping the windoooows?"

"Almost. Just a little more...!"

Calling back to the voice summoning him, Ren dipped the rag in his hand into the water.

The water in the bucket had been drawn from an Underworld stream — red as undiluted ink and cold as ice. Just wringing out the rag was enough to make his hands go numb.

"Never thought I'd come all the way to the Underworld just to end up helping clean the Demon King's Palace."

"You're the one who said you wanted a change of pace, humaaan."

A dark fairy came fluttering through the air.

It was a fairy species with translucent wings patterned in black, about sixty centimeters tall. They were said to be the largest among the airborne fairy varieties.

On the surface they were considered an endangered species, but it turned out they had actually mass-migrated to the Underworld. In fact, several hundred dark fairies worked as household helpers right here in the Demon King's Palace.

"This place is huuuge, after all. There's plenty of cleaning to help with."

"Yeah, I get that, but still."

He turned back to the window — taller than he was — and nervously glanced down.

Sheer cliff.

A rust-colored precipice plunging hundreds of meters with no visible bottom stretched wide open below, eerie green gas billowing endlessly from its depths.

"That gas is definitely poisonous too, right..."

The Underworld — Vena Asra Doll.

An underground world that humanity had yet to fully chart since the dawn of recorded history.

In place of the sun, a sinister aurora illuminated the horizon, and blood-colored fog hung in the air as if it had a will of its own. The atmosphere was raw and sticky, and just breathing made him feel like something was slowly eating into his lungs.

"...So. About this window-wiping job — isn't this way too life-threatening?"

Five days in the Demon King's Palace.

Figuring he couldn't just sit in his room forever, he'd asked the dark fairies for something to do as a change of pace. The chore they'd given him was window-wiping — but he never expected it to turn out like this.

"When they said 'window-wiping,' I thought they meant the hallway side — not the outside of the building..."

One slip and he'd plummet straight off the castle wall. And below that, as he'd just seen, was a cliff full of toxic gas. Right now he was barely standing on the window ledge with the tips of both feet, and every gust of wind made his whole body lock up.

"If you fall, just fly through the air."

"Humans can't fly!"

"Is that sooo? But if you can't fly, how'd you even get down here from the surface?"

The dark fairy bobbed up above his head.

"There were lots of scary creatures, right?"

"Yeah. Tons of them. Let's see... I explored the Vanessa Wetlands — the Demon Lands — and came through the gate beyond them into the Underworld, and then got chased by magical beasts and poisonous creatures until I barely made it to the Demon King's Palace alive."

"Then window-wiping shouldn't be scary at all."

"It's a completely different kind of scary... whoa — AAAAHHH!?"

A horizontal gust of wind shrieked past him.

The instant his feet slipped, Ren let go of the rag and grabbed the window ledge with both hands.

"I'm gonna die!? What am I doing, dying before I even get the Demon Seal!?"

"Just fly through the air."

"I told you, humans can't fly!"

He hauled himself up and over the window with both arms.

Just wiping ten panes of glass had left his entire body drenched in cold sweat.

"Good work."

"I lost count of how many times I screamed..."

The moment he touched down in the corridor, his legs buckled and he sagged against the wall.

And then —

An ear-splitting shriek came echoing down the hallway.

"That's wroooong. You have to sweep the broom along the grain of the carpet."

"Oh, enough already — shut up, shut up! As long as the dust gets picked up, what does it matter!?"

"If you sweep too roughly, the carpet gets damaged. Didn't you know thaaaat?"

"I said SHUT UUUUUUUP!"

A silver-haired girl came charging down the corridor, gripping a broom with single-minded fury.

"Kyelse?"

"Oh — Ren! Help me, that obnoxious little dark fairy keeps nitpicking everything I do. You want to know just how obnoxious it is? Well—"

"If you've said 'obnoxious' that many times, I think I get the picture."

Ren shrugged at the pouting Kyelse.

Dragon Princess Kyelse — her blue-tinged silver hair flowed like fine silk threads, and her pale emerald eyes were as beautiful as real gemstones. She looked perhaps sixteen or seventeen in human terms, her features radiating both loveliness and a natural nobility.

She had a fairytale-like, ethereal air about her, but Ren had been told this appearance was actually a transformation created through spellwork for traveling purposes. Kyelse's true form was a Heavenly Silver Dragon — an extremely rare dragon species — and she was the Dragon Princess who ruled over the dragons of the surface world.

"...But why do you have a broom?"

"A change of pace. Sitting around thinking about things doesn't suit me."

Kyelse balanced her finger on the center of the broom handle and twirled it around.

"Besides, the thing the Silent Agency stole was the Demon King's Demon Seal, so the demons are obviously the ones who know best how to deal with it. There's no point in me thinking about it."

"Ah... so you had the same idea as me, then."

The Encore — the ultimate treasure said to have been written by the Brave Hero Eleline.

The place most likely to hold it was the land known as the Isle of the End, where Eleline had fought the End War three hundred years ago.

"We can't get into the Isle of the End without the three Seals, and I've got the Goddess's Seal. Kyelse, you have the Dragon Seal. So the last one — the Demon Seal..."

"Was stolen by a member of the Silent Agency called Isis. Honestly, that useless Demon King."

The dragon girl twirled her broom and sighed.

Having the Seal stolen had even Kyelse looking deeply troubled at first, but Ren knew she'd finally managed to put it behind her as of yesterday.

Now, however, her frustration seemed to have redirected itself toward the Demon King who'd lost the Seal in the first place.

"Ambush or not, to have the Underworld's greatest treasure snatched away that easily..."

"Well... it really was strong, though. Not that it's much of an excuse."

The Silent Agency — the ones who had interrupted Ren and Demon King Versalem's battle.

The one who'd stolen the Seal was Isis. And the one who'd blocked their pursuit, attacking them head-on, was the Spirit Beast who called himself Discant.

"My name is Discant. The unblemished beast, the one who heralds the storm."

"My Invincible Suggestion operates as a law of the world itself."

Five days had passed since that fierce battle —

And looking back, those words didn't seem like a lie at all.

Demon King Versalem's spells and Ren's spirit sword — every last one had been nullified by the Spirit Beast Discant's Invincible Suggestion. And even after the Suggestion was broken, the two of them together still couldn't defeat the Spirit Beast.

"If Elise hadn't come running when she did, I don't even want to think about what would've happened..."

"I know."

Kyelse stopped twirling the broom.

She turned her face away, looking uncomfortable.

"...I went too far. I'm sorry if it sounded like I was blaming you."

"Nah. I was frustrated too — about a lot of things."

Not a single scratch from Ren's blade had landed on the Spirit Beast Discant's skin after the Invincible Suggestion wore off.

...If it had been the Sword Saint Shion or Knight King Zelbright fighting Discant instead of me...

...the outcome would've been different.

Just how far short he still fell as a single swordsman, stripped of the spirits' power — that battle had driven the point home painfully.

"At least I found out before heading to the Isle of the End. That things like him are out there."

"Was it really that formidable?"

"Yeah... from my perspective, every opponent I've fought so far has been unbelievable, but that one was different from the rest in a way that wasn't just raw strength."

The biggest difference had to be the spirits' reaction when facing the Spirit Beast Discant.

Gnome and Salamander — the primordial spirits who normally cheered Ren on — had cowered before Discant, too terrified to move.

"The bond between us and the spirits stretches back to the creation of the world. There is no room for you to intrude."

"Discant talked like he knew Gnome and Salamander personally. But at the same time, he called the Silent Agency 'we' and drew a clear line between them and the spirits."

"...Hmm."

"There are definitely similarities between the Silent Agency and spirits. Discant's voice couldn't be heard by the Demon King, either."

"Same for me."

Kyelse gave a small nod.

"It's been that way since three hundred years ago. I never knew the Silent Agency could speak at all. If you hadn't told me, I never would have learned that they had names like Isis and Discant. But that's beside the point. There's something more pressing to consider."

"How to break through the barrier around the Isle of the End — isn't that right?"

The words that followed Kyelse's came from around the corner she'd just run from — a voice that carried a sense of warmth and calm.

"Fear-senpai?"

"I've been looking for you, Ren — and you too, Kyelse."

A graceful, golden-haired girl stepped into the corridor and turned an easy smile their way.

"I wanted to discuss the Seal situation, but neither of you were in your rooms. Searching this enormous mansion was quite the ordeal. Isn't that right, Elise?"

"Yeah yeah — we had to stop every dark fairy we saw and ask where you two were."

Trotting up behind Fear was a lively young girl with dark skin.

Archangel Fear and former Demon King Elise.

Both were legendary members of the Three Princesses who had quelled the End War alongside the Brave Hero Eleline.

"So... about the Demon Seal you two were discussing. We've been racking our brains over it too. Whether to take it back by force or find some other way — it's one or the other, but neither option's exactly easy."

"And yet, Elise, weren't you sound asleep just a moment ago looking perfectly content?"

"That's fine, that's fine — you need rest to use your head. Besides, Kyelse was doing the same thing, right? Walking around with a broom in a hallway like this — you got tired of thinking about the hard stuff and decided to do some cleaning for a change of pace?"

"I didn't get tired of thinking about it. I was thinking desperately about the Seal too... it's just that I was in the mood to move my body a little, and then—"

Kyelse started twirling the broom again.

"Ren invited me to help kill time."

"Why am I the scapegoat!?"

"Jokes aside — what about on your end? Especially you, Elise. You shut yourself in your room last night saying you were going to discuss the Seal with the Demon King."

"Total bust. My useless little bro strikes again..."

Elise hopped up onto the windowsill with a little skip.

She'd settled on the very window Ren had just been wiping. The dizzying cliff was right below her, but she showed not the slightest hint of fear.

"What about the palace advisor? That Housekeeper."

"Lulu's meeting with the Five Great Disasters right now. It'll take a while, so we figured we'd put our heads together separately. That's why we were looking for you two. So how about you, Ren? Come up with anything interesting?"

"Not at all. I don't even really understand how the Seals work..."

Watching a dark fairy drift past, Ren shook his head.

"Oh — but just to confirm something. Right now I have the Goddess's Seal and Kyelse has the Dragon Seal. That's two of the three Seals, right?"

"That's right, yes."

Fear nodded with her usual composure.

"This is a review of what the Goddess Resflaze told us, but three hundred years ago, after fighting through the End War, Eleline wandered the world alone. Afterward, he visited the Goddess and asked her to seal off the island where the End War had taken place."

"Make it so no one can ever set foot on that battlefield again. But..."

"There's one exception."

"If someday — years from now, maybe decades, maybe centuries — someone appears who can be entrusted with everything in my stead, then give them the Seals to undo it."

The island sealed by the combined power of Dragon Emperor Calra, the Goddess Resflaze, and Demon King Versalem.

To reach it, three Seals were required — and Ren had been told they were the ultimate barrier-breaking treasures in existence.

"If we have two Seals..."

"If you're wondering whether we can force our way through the Isle of the End's barrier — don't."

Kyelse's answer came without a moment's hesitation.

Not difficult, not challenging — "impossible." The bitterness in her expression as the dragon girl looked up at him was rare to see.

"Even I couldn't do it, I think."

"Even you, Kyelse?"

"I've never tried, but even if I did break through, my entire body would be wrecked by the time I made it. Given that the Silent Agency could attack us afterward, it's not a realistic plan. And on top of that..."

Her sharp eyes dropped to Ren's hands.

"A while back, Fear and Elise gave you 'charms' as activation catalysts for the ancient summoning spell — Fear's feather and Elise's jewel. Before the fight with the Demon General of Blaze Achendia."

"For now, don't think of Fear and Elise's divine implements as summoning catalysts — think of them as a powerful protective barrier and keep them on you at all times."

Divine artifacts imbued with angelic and demonic power functioned as protective barriers in their own right.

The fierce battles Ren had survived thus far — he'd been aided by that protection more than he probably realized.

"You've got Fear and Elise's divine implements plus two Seals. You figured that might be enough to withstand the Isle of the End's barrier, didn't you?"

"That's exactly it. But I guess it's no good..."

Feeling caught out, Ren opened both hands to show her.

Fear's feather in his right hand. Elise's jewel in his left. He'd pulled them out because he'd hit on exactly the idea Kyelse had read him on and wanted to ask about it.

"I don't dislike that adventurous spirit of yours, Ren. Nor the idea that my and Elise's divine implements could break the barrier even without the final Seal."

The golden-haired Archangel let out a soft laugh.

"But this time, it would be wiser to look for another way. If even the Silent Agency gave up on breaking through and resorted to stealing the Seals instead, that should tell you just how powerful the barrier around the Isle of the End really is."

"Yeah..."

A barrier that even Isis and the Spirit Beast Discant couldn't touch. If they went there one Seal short, who knew what would happen to a human body.

"No wonder Lulu told me I'd get ripped apart."

Ren sighed and stared up at the ceiling.

"To be precise, she said 'your body would decompose into roughly two hundred pieces and become seaweed scraps.' But honestly, if she's gonna say that, I kinda want to see what actually happens. What do you think, Ren?"

"Don't ask me to agree to that."

For some reason, Elise was supplementing this detail with an excited grin on her face.

"But if that's the only other option, we'd have to find the Silent Agency and take the Demon Seal back. And I really don't see how we can pull that off..."

"I know."

Kyelse herself looked weary as she nodded.

"They've spent three hundred years hiding from us since the End War. I doubt we'd find them now just because we're desperate. Call it intuition, but based on everything you've described about your encounter with the Silent Agency... the place they're hiding is somewhere completely beyond our reach."

"My encounter?"

"You said they seemed similar to spirits, remember?"

Elise spoke up from her perch on the windowsill.

"When we fought them three hundred years ago — well, we couldn't hear spirits' voices in the first place, so we had no way to compare. The best we could do was 'do they look like spirits?' We were too busy fighting back against their attacks to think about what they really were."

"Exactly. If they really are close to spirits like you say, then where they're hiding is easy enough to guess."

Tap...

Kyelse tapped the broom handle against the bare corridor wall.

"A space that exists nowhere in the world. Ren — think back to where you first met Gnome."

"—The spirits' dwelling."

He remembered when Kyelse had led him toward the Valley of the Dragon.

They'd taken a shortcut through underground ruins because going around the mountain range would have taken too long.

That was the Isquercel Basement Temple.

The place where he'd first met the party "Sacred Vessel of Canaan Pilgrimage" — and where he'd found a spirit dwelling and been pulled into Gnome's space.

...That time, it was an endless desert of golden sand.

...A scorching space with no trees or grass, and Gnome was just sitting there.

"What happened to the temple? Where did we get sent?"

"Spirits have the power to reshape a space into their preferred environment and claim it as their dwelling. For Gnome, this desert is her favorite habitat."

Thyrus the Fulltype and Premier the Aria — two officers from the Sacred Vessel of Canaan Pilgrimage had been there too. He'd been forced into a life-or-death "doll game" with Gnome's Golem in that place.

A spirit's space.

What Kyelse meant by "somewhere completely beyond our reach" was —

"Oh — right. That place was..."

"Exactly. Dragons, angels, and demons can't enter a spirit's dwelling. Only humans can. If the Silent Agency really is similar to spirits, then they might be able to create their own spaces the same way."

The Silent Agency's base — located somewhere unknown in the world.

Finding it would be nearly impossible, and even if they did, only Ren could go in. If the Silent Agency was waiting inside, he'd be overwhelmed in an instant.

"As far as we know, the Silent Agency consists of a humanoid entity called Isis, and a Spirit Beast called Discant, and—"

"Don't forget the white-haired girl who called herself Misty."

"...Her."

A face flashed through his mind, and a heavy breath escaped him before he could stop it.

The two members of the party "Venus Light" who'd been stranded in the Underworld's forest — their leader, a swordsman called Dan, and Misty, the girl who'd been traveling at his side. According to Lulu, Misty had really been a member of the Silent Agency — the one who destroyed the Gate of the Underworld in the Vanessa Wetlands. Dan had known nothing; she'd used him to slip into a human party and destroy Gates in ruins across the world.

"Come on, you too — bow your head, Misty."

"...Thank you."

"Ha ha ha! She's not very honest, but she's a sweetheart deep down. Cut her some slack."

Even looking back, he couldn't quite see her as a bad person. He almost said so out loud, but he couldn't bring himself to in front of Kyelse and the others, so Ren held his tongue instead.

"In any case, we know of at least three End War remnants."

Kyelse settled onto the windowsill next to Elise.

Her hair whipping in the wind that swept past them —

"There could be more in hiding. There's no way we can send you in alone against their base."

Which meant that finding the Silent Agency and reclaiming the Seal was off the table.

"So what options do we have left?"

"None."

"None that we can see."

"Beats me."

All three — Kyelse, Fear, and Elise — wore defeated expressions in unison.

Not that this conclusion was a surprise. They'd more or less expected it since the night the Silent Agency attacked.

Five days of deliberation had simply failed to overturn it.

"Then it's a war of attrition after all. If we can beat them when the Silent Agency comes for the other two Seals..."

But there was no telling when, where, or how the attack would come.

If they went back to the surface, for instance —

The Silent Agency could strike while Ren was asleep in his room at an inn, or while he was alone in the shower.

"Forget sleeping soundly — I'd have to stay on guard all night. I might not even be able to sleep alone..."

"I wouldn't mind."

"Huh?"

"I always say this, but I sleep better with someone than alone. Starting tonight is fine with me."

Kyelse said this with a perfectly straight face.

"It's settled, then. Ren, sleep in my room starting tonight. Just bring one pillow."

"Hey! That's not fair, Kyelse. Hey, hey, Ren?"

"...Fear-senpai? What's with the arm-grabbing all of a sudden?"

Fear had casually hooked her hand around his elbow and was gently tugging.

"I'll take bath duty. The bath is when you're most vulnerable — no sword, no clothes. That's the perfect opportunity for the Silent Agency to strike. So a hand-to-hand fighter like me is the most qualified to join you and keep you safe. So, Ren? Starting tonight, give me a heads-up whenever you're about to take a bath. My my — this situation might not be so bad after all."

"Aww, no fair — Kyelse and Fear are getting all the good parts."

And then Elise jumped off the windowsill too and grabbed his left elbow.

"Then I'll stand guard when Ren changes! The moment he's pulling his shirt off with both hands occupied — they'd never pass that up. Actually, I'll just dress him myself!"

"...Um, all three of you? I was trying to have a really serious conversation here."

"So was I."

"I'm being perfectly serious too, you know. I won't deny there's an ulterior motive, but still."

"Right?"

The Three Princesses nodded at each other in unison.

But then, just like that —

"Well, jokes aside... there's one more thing. An idea I discussed with Elise."

The golden-haired Archangel raised one elegant finger toward the ceiling.

"If the Seal has been lost, then we simply make a new one."

"Make a new Demon Seal?"

"A replica. Think of it like a house key — you make spare copies for every member of the family. There's no rule saying only one key can open the barrier. Right, Elise?"

"In theory, yeah."

Elise was still tugging on his elbow.

"The Demon Seal was created using the Demon King's secret arts. I wasn't involved, but there is a Demon King who actually made the original — so logically, using the same method to make a replica should be possible, but..."

"Oh — so that's an option! Would it actually work as a replacement?"

"Yeah. If we went all out, we could probably make at least one replica."

"...'All out'?"

That was not a reassuring choice of words.

And despite Elise's usual cheerful tone, a shadow had crossed her face the instant she said it.

"The Seals were designed to be impossible to replicate. If anyone could copy them easily, the Silent Agency would've done it already, right?"

"Ah. Good point..."

"Bending the rules to make a replica takes serious stamina and spell-power. And unfortunately, my little bro's in pretty bad shape right now."

The fierce battle against the Spirit Beast Discant.

In that fight, the Demon King had shielded Ren — and taken injuries so severe he couldn't stand on his own.

"That creature's flash is not mere brainwashing. Its true nature is the Light of Negation."

"To a demon, that light is the most brutal thing there is... a Purifying Fire."

Now the Housekeeper Lulu was treating him around the clock.

His life wasn't in danger, but even a Demon King wouldn't recover from that easily.

"He's in no condition to make a replica of something that's supposed to be one-of-a-kind. Even if we forced him, the result would just be a low-purity knockoff. That wouldn't be enough to get past the Isle of the End's barrier. Worst case, the replica shatters mid-transit and we'd all get caught in the barrier. Guaranteed wipe."

"...I'd really rather avoid that."

"Right? Ideally I'd make the replica myself, but..."

Elise smiled ruefully.

"If I tried something like that in this body—"

"It would exhaust her power entirely and force yet another reincarnation."

Soft footsteps echoed down the corridor.

Trailing a retinue of over ten dark fairies, a demon in a housekeeper's dress appeared — her hair a striking blue.

"I considered the same option, but in their current states, neither the Demon King nor Lady Elise can produce a replica without placing too great a strain on their bodies. I cannot recommend it."

Housekeeper Lulu.

She had served every generation of Demon Kings since the distant past and was the only person who knew the full layout of the Demon King's Palace — a labyrinth of bewildering complexity.

Her other face was that of Luluphonica, the Demon General of Ice — one of the Five Great Disasters. The most senior of the Five, and in practice, the Demon King's chief advisor.

"Ren, I apologize for the wait. I'm sorry for all the trouble over the Demon Seal."

"Don't worry about me... You've been working hard too, Lulu — reaching out to the Five Great Disasters, thinking everything through."

"The consultations went well enough, but..."

The blue-haired girl pressed her fingertips to her forehead with a sigh.

"Direct teleportation to the Isle of the End using the Gate of the Underworld's transfer function. Or developing a protective spell apart from the Seals that could shield us from the barrier. Failing that, some method to weaken the barrier itself. ...We examined every possibility we could think of, but the conclusion is that none of them are feasible. The sole viable fallback is exactly the method you were also considering."

"Having the Demon King make the replica himself? But how is he doing?"

"Taking Discant's light twice is what did it."

The Housekeeper answered without hesitation.

"That attack is the same type that forced Lady Elise into reincarnation three hundred years ago. Even a demon's high vitality and regenerative ability can't recover from it easily. For the Demon King to recover enough to produce a high-purity replica... two years, at the earliest."

"Two years!? That long!?"

"Think of it this way — the Demon Seal is an extraordinarily delicate piece of glass craftsmanship. But if the artisan severely injures his arm, even the finest craftsman has no choice but to rest. The Demon King's condition is the same. He may have no trouble with daily activities, but completing a unique protective spell of the Seal's caliber is another matter entirely. A replica forced out now would simply be rejected by the barrier."

"...That's what Elise told me too. That a forced replica wouldn't work."

"Yes. Which brings us back to the same conclusion."

Lulu bowed her head formally.

No options. Even the Demon King and the Five Great Disasters together hadn't been able to find a way to compensate for the stolen Demon Seal.

"I'm sorry we couldn't do more."

"No — that's not something you need to apologize for, Lulu."

"—And that is the result of our orthodox analysis. Since there's no other way, let's gamble on an unorthodox one."

"Hm?"

Elise was the first to react to Lulu's words.

"Hey, Lulu? What do you mean, unorthodox?"

"Exactly what it sounds like. I'd like to try filling the gap left by the Demon Seal using a secret trick of my own — one I've been keeping in reserve. Success is about fifty-fifty."

"...Something I don't know about?"

"Surely everyone deserves one or two secrets they've never told a soul. It wouldn't be very demonic otherwise, would it?"

The Housekeeper scooped Elise up into her arms.

She gazed down at her with a look of tender affection, as if watching over her own child.

"Leave it to me. I will see to it that you reach the Isle of the End, Lady Elise."

"Hmm."

Held aloft, the former Demon King stared up at the Housekeeper's face.

"I don't really get what you're planning, but you're not going to use up all your power and die on us, right?"

"...Lady Elise, your intuition is a little too sharp for comfort."

The blue-haired demon smiled softly.

"Please don't worry. I still have duties to fulfill as Housekeeper. If I were gone, there'd be no one left to direct the dark fairies."

"You sure? Because I don't want to lose you, Lulu."

"Yes. And to ensure I don't do anything reckless, I'll ask Ren to be present as a witness."

"Me!?"

He hadn't expected to be named — for a moment, he doubted his own ears.

The conversation between Elise and Lulu had been... not exactly ominous, but there was a palpable tension between them. And this had come right on its heels.

"Having an impartial third party like you, Ren, bear witness would lend this more credibility."

"Uh, what?"

"What I mean is this: I will prepare something to take the Demon Seal's place, and during the ritual to create it, I'd like you to be present. You can report to Lady Elise afterward."

Her tone was gentle. But those eyes — crimson as a full moon, blazing with quiet intensity — brooked no refusal.

"Ren, would you be willing?"

"...I don't mind. Elise?"

"Hmm. Well, if Lulu says so, she must be confident. And if she's asking you instead of me, she's probably got a reason for that too."

Scratching the back of her head, Elise said —

"Ren, would you do it?"

"Sure. If I'm the right person for it, I'll be there. For this ritual or whatever it is. Just — fair warning — if the 'witness' part turns out to actually be another duel like the Demon King's, I'd appreciate a heads-up..."

"Of course. I'm already well aware of your qualities, Ren. That's precisely why I'm asking you to attend my ritual."

The Housekeeper pinched the edges of her skirt and gave a graceful curtsy.

"I need some time to prepare, so I'll take my leave. Ren, I'll come for you this evening."

The blue-haired girl departed with her train of dark fairies.

Watching her figure disappear around the corner —

"What do you suppose she's planning?"

"No idea. The Dragon Seal I could weigh in on, but when it comes to the Demon Seal, I'm out of my depth."

Fear and Kyelse murmured quietly.

And amid them —

"Hmm. I wonder. It's not like Lulu to keep secrets from me."

The former Demon King — a young girl — rested a finger on her lips and gazed up at the ceiling.

"I'm so curious. How is she going to make a replacement for the Demon Seal? Lucky you, Ren. When tomorrow comes, you'd better tell me everything in secret, okay?"

"...If it's something I can actually understand and explain."

Spellwork had never been his strong suit, not even back at Holy Fiora Journey Academy. If this involved the Demon King's secret arts, he doubted he'd grasp any of it even watching the real thing.

"I probably won't understand a single bit of it."

He threw up his hands in surrender and let out a long sigh.

A night that glowed blue.

The crimson currents that had blanketed the Underworld's sky sank below the horizon, and freezing blue currents blew in from the northern glaciers.

"Huuuman, wake uuup. It's nighttiiime."

"Getting woken up with 'it's nighttime' instead of 'it's morning' is a first for me..."

Shivering in the cold, Ren answered the dark fairy's call and stepped out of his room. Walking through the corridor under the glow of chandeliers that burned the same as during the day, he followed behind the dark fairy.

"Still, she said tonight, so I figured it'd be midnight — I didn't expect 'tonight' to mean this close to dawn... Not that you'd understand if I told you, right?"

"Night is night, got iiit."

"But by Earth's standards, the sun's about to come up. It's just — maybe this is a dumb assumption, but I always figured nocturnal demons would prefer the dead of night."

"Listen up, huuuman. Shadows are darkest right next to where light hits. Faraway spots actually get brighter from reflected light, you knooow. Same goes for night. The darkest part isn't midniiight."

"...Meaning?"

The dark fairy turned around.

"Meaning, you seeee —"

"The darkest and coldest moment is just before dawn."

The voice came from directly behind him.

He felt a chill on the nape of his neck, like a northern wind —

"Lulu?"

"My apologies. Silly me — the Demon King's room took longer to clean than expected, and then there was feeding the demon beasts. I thought you might arrive first, so I hurried to catch up."

The Housekeeper gave a small, apologetic bow.

Her outfit was the same as during the day — a maid's dress with a white headpiece.

"Really? You mentioned that preparing a substitute for the Demon Seal required a special ritual, so I figured you were getting ready for that."

"That too, of course, but I am rather fond of my duties as Housekeeper, you see... Dark fairy, well done. I've prepared maple syrup in the kitchen for you."

Sending the messenger fairy on its way, Lulu continued.

"Now then, Ren. Allow me to guide you to the underground chamber."

She started down the vast, seemingly endless corridor.

He had assumed the meeting point was the destination, but apparently they were going deeper still.

"Walking in silence is tedious, so let me tell you a little story. When you first visited, I gave you a tour of the estate, but... let's see. For a topic you might find interesting — how about the history of the Demon Kings?"

"The Demon Kings?"

"Yes. You already know the former Demon King Elise and the current Demon King Versalem, so let us go all the way back to the very beginning — to the era of the master who built this estate. The First Demon King."

Her walking pace stayed the same.

Lulu led the way through corridors that twisted like a labyrinth, and the first words out of her mouth were:

"The First Demon King was exceedingly cruel, cunning, and cowardly."

"...That's quite the opening."

"Yes. But there truly is no other way to describe that demon. It may surprise you, given the Demon Kings you know — Versalem and Elise."

Turning left at a crossroads, Lulu pointed to the right-hand passage on the opposite side.

"The Demon King's Palace is the same. It was never built to display authority — this labyrinth was nothing more than a shell to protect its master from outside enemies."

"Ah, yeah, I can kind of see that..."

Hundreds of demons lived here, and still the place was absurdly vast. Even now, walking through the corridors, he hadn't passed a single other demon or dark fairy. On top of that, most of the vases and paintings lining the halls were apparently rigged with traps.

All of it had been a means of self-defense.

"But this feels kind of unusual. Was the First Demon King really that awful — even to you, Lulu?"

"Perhaps so."

Revulsion might have been the closest word.

The Housekeeper — the demon who carried herself with a mature, gentle poise toward everyone — let unmistakable disdain bleed through when it came to the First Demon King alone.

"The First Demon King's thirst for dominion knew no bounds. Wanting to rule the Underworld forever, the First Demon King perfected the secret art of reincarnation — then hid that identity, posed as an ordinary demon serving the Demon King, and lurked within the palace, quietly amassing power. All to overthrow the reigning Demon King and reclaim the throne."

"...That kind of obsession is genuinely terrifying."

"Yes. But even for such a wretched demon, a turning point arrived."

Lulu continued without missing a beat.

"While serving in secret within the palace, something like parental affection took root — watching the Demon King grow into a fine ruler, developing an attachment. Surrounded by a Demon King who relied on them, and dark fairies who adored them... eventually, the First Demon King chose a new title: Housekeeper of the Demon King's Palace."

"...Housekeeper?"

"Ren. Do you remember what I told you while we were walking through this corridor? When you first saw these trap-filled halls —"

"Lulu? Don't tell me the whole estate is rigged with traps like this?"

"A hobby of the First Demon King."

Come to think of it.

When he had first heard that explanation, something had nagged at the back of his mind.

Lulu, who attached "-sama" to everyone — Ren, Elise, the Demon King — why had she alone referred to the First Demon King without any honorific?

And then he recalled what Elise had told him about Lulu's role.

Demon General of Ice, Luluphonica, holds a special place even among the Five Great Disasters.

She has lived in the Demon King's Palace longer than anyone and has served as an advisor to every Demon King throughout history.

The most senior of the Five Great Disasters.

At every Demon King's coronation, she had stood as their final trial — a rite to test whether the successor could stand on their own. She had done so for Elise. And for every Demon King before her.

"No way..."

"I assure you, I have no desire to reclaim the throne anymore?"

The blue-haired demon stopped.

She turned, and on her profile flickered a bitter, hollow smile tinged with regret.

"All the First Demon King Luluphonica can do now is watch over every last one of her kin."

His vision lurched.

A sound like the droning of countless insects struck his eardrums. The moment it registered, space warped violently around Ren and the Housekeeper girl alike.

"This is my own secret teleportation device. For traveling to the depths beneath the Demon King's Palace."

Her voice refracted in layers.

When Ren opened his eyes, he was in a dim chamber lit by pale blue flames.

"Please keep this between us — not a word to Elise or the Demon King."

The blue-haired girl emerged faintly from the gloom.

She still bore traces of Lulu the Housekeeper, but strange purple markings now surfaced on her slender arms and forehead, and small, twisted horns peeked from the top of her head.

"...Lulu? Is that your..."

"This is how I looked as the First Demon King. Though the change isn't all that dramatic, wouldn't you say?"

The Housekeeper —

No. The First Demon King, Luluphonica, rested a hand against her shapely chest and let out a small, amused laugh. She had known full well he would be surprised, and she was enjoying every moment of it. That was the impression she gave.

"Surprised?"

"...I've heard demons like their mischief, but still."

"Yes. That is a trait all demons share."

A crimson full moon —

Luluphonica gazed at him with demonic eyes so deep they could swallow a person whole.

She stepped forward with an elegant, composed motion.

"I'll be borrowing your left hand."

She took it and enclosed it between both of hers.

"Your right hand already carries the Goddess Resflaze's Angel Seal, so I will take this one —"

In that instant.

A whirlwind erupted around Luluphonica and Ren, and sparks like bolts of lightning burst forth.

"Ow—!?"

"I will generate a Demon Seal replica and engrave it semi-permanently into your body. This way, there is no risk of the Seal being stolen again."

Lightning condensed amid a storm of blinding light and sound. It gathered into Luluphonica's hands — into the back of Ren's hand — forming a deep blue crest.

Countless sparks flew off in the process, scattering into the pitch-black darkness.

...It's like forging a blade.

...Like hammering white-hot iron in a shower of sparks.

"It will hurt, but please endure it a little longer."

Sweat poured from the First Demon King Luluphonica's chin in heavy drops.

Beneath her vivid crimson eyes, dark circles had already formed. She looked as though she were shaving away her very life to forge the Seal.

"Lulu!? Are you okay...!?"

"...'Okay' is far from the word I'd use... My power has been weakened considerably from all the reincarnations I've undergone... But it still takes less of a toll on me than it would on the exhausted Demon King, or on Elise so soon after her own reincarnation."

The First Demon King pressed on, biting her lip.

Lightning racing through the chamber coiled around her arms, searing her skin.

"Seal generation is a secret art derived from the Demon King's own techniques. Since it is my art, I should be able to reproduce the Demon Seal that the Demon King created — with high precision."

A sharp crack echoed through the chamber.

The wind that had been whipping her hair and clothes died down, the searing lightning vanished. The room returned to its dim quiet, lit only by pale blue flames.

"That... should be... every—"

"Lulu!?"

The blue-haired girl's strength gave out and she crumpled.

"Ahh, it will be a while before I can fulfill my Housekeeper duties again... I'm exhausted..."

"...'Exhausted' is all it is?"

"I wanted to entrust the Seal to you. That feeling made this the obvious thing to do — nothing more."

Seated on the dark floor, the First Demon King spoke between ragged breaths.

"Ren."

She lifted her face.

"On the Isle of the End... you will learn many things. Things you want to know, and perhaps... things you would rather not."

"I'll be honest. On that island sleeps a past that we would rather humans never learn of."

Was it coincidence?

The words the First Demon King had spoken echoed something he had heard from the Goddess of Heaven.

"But don't be afraid of knowing."

"——"

"What you choose to do with the knowledge you gain — that decision will always be yours."

Luluphonica exhaled weakly.

Ren knelt before her and gave a firm nod.

"...Thank you. I promise — I'll find the Encore on the Isle of the End and bring it back."

"I look forward to it. And with that, I have given you everything I can. Now go."

"Go?"

"When next we meet, I would be delighted if it were as Elise's husband."

The Housekeeper answered with a smile.

At the same moment — a faint tremor.

Four towers rose from the floor around Ren, front, back, left, and right.

Triangular, pyramid-shaped Obelisks he had seen before. Four warped Obelisks like the fangs of a beast, and at their center, jet-black mist gathered to form a solemn doorway.

"A Gate!?"

"Please take care of Elise. She is someone the Underworld needs."

Black mist enveloped Ren.

Beyond it, Lulu — having finally managed to rise — bowed deeply. But by the time she did, Ren had already been teleported from the Demon King's Palace.

...Bright.

The first thing that struck Ren's eyes when he opened them was the brilliance of the sun.

Sunlight — something never seen in the depths of the Underworld. It poured in from the horizon, painting over the dark sky with blue.

"Where... am I?"

He was standing on an unfamiliar beach.

The sea before him was crystal-clear and shallow, its surface shimmering in vivid Emerald Green. The fine white sand underfoot wasn't round but shaped like tiny pointed stars — coral fragments, perhaps.

"Orperia Beach. That is what the local fishermen call this shore."

The sound of footsteps on sand.

A golden-haired Archangel walked along the water's edge, her hair streaming in the sea breeze.

"Fear!? When did you —"

"Almost the same time as you. I was worried about how you were doing when a dark fairy summoned me. Kyelse, Elise, and I were called to the audience hall of the Demon King's Palace, and... the hidden Gate of the Underworld had been activated."

Fear pointed to the sparkling sea.

"This is a shore on the northeast coast of the Yumeru Continent. The seas here are calm — it's the most convenient departure point for the Isle of the End."

"So this isn't the Underworld anymore, it's..."

"You passed through the Gate and returned to the surface. You've been teleported to the nearest point to the Isle of the End."

Behind Fear, Kyelse stood gazing at the vivid horizon.

"I never would have guessed the audience hall hid a Gate like that. Elise, did you know?"

"Nuh-uh. I kinda remember hearing about it forever ago, maybe? The palace is just way too big — I don't even know where anything is."

Elise shook her head without a care in the world.

"A-Anyway, more importantly, Ren — let me see your left hand... Huh. Lulu really put in the work. I can feel a reaction similar to the Demon Seal."

"Really? I don't feel any change at all."

He had braced himself when told the Demon Seal replica would be embedded into him, but now that it was done, his hand looked no different than before — just like with the Angel Seal. No foreign-object sensation whatsoever.

"Mm-hm. That's the First Demon King for you."

"Huh? Elise, did you just —"

"You think I wouldn't notice?"

Elise murmured under her breath and gave a knowing wink.

"I don't know who else in the palace knows, but as long as Lulu wants to keep it secret, I figure I'll keep quiet too. Anyway — this should let us get past the island's barrier, right? Kyelse, are they here yet?"

"Should be any minute now."

Kyelse's gaze remained fixed on the horizon.

"It has to fly across the ocean, after all. Even flying through the night, it takes time."

"Hey, Kyelse? What's flying?"

"That would be —"

Just as Kyelse turned to answer —

Ren's field of vision was blotted out by an enormous shadow. A colossal presence overhead — he felt it an instant later.

"...A dragon?"

And not just any dragon.

The dragon most commonly seen by humans was the Wyvern, which reached seven meters in length. But this creature soaring across the blue sky dwarfed even that — a massive body adorned with a radiance as vivid and shifting as an aurora.

A dragon of breathtaking, prismatic color.

Ren could think of only one dragon that matched.

"Calra!?"

"You have grown a little — just a little — stronger. By a dragon's sense of time, it feels as though your visit to the Valley of the Dragon was only yesterday."

Dragon Emperor Calra.

The spirit-king dragon that guarded the sacred domain where all dragonkind gathered — she had crossed the sea and was flying over the skies of another continent entirely.

"I have heard the general situation from Demon King Versalem. So the Encore is most likely sleeping on the Isle of the End, then... If remnants of the End War's calamities remain there, securing the Encore should be the highest priority. Haste would be wise."

"Meaning?"

"Meaning this."

The spirit-king dragon descended onto the beach with a tremor that shook the ground.

Kyelse leaped lightly onto the enormous back — a body the size of a small hill. Fear followed, and Elise scrambled up using Calra's tail, scaling the dragon's back with ease.

"We'll have Calra carry us to the Isle of the End. A human ship would be torn apart trying to cross the barrier. And more importantly, I get seasick."

"...Wait, but we've got all three Seals now, right?"

They had just established that the three Seals would let them reach the Isle of the End.

He could accept that Calra's flight was faster than a human ship, but what did she mean about the ship being torn apart?

"Sister, I will carry Ren in my arms."

Calra's massive forelimb appeared before him in an instant.

"If he just rides on my back, the barrier's gales might blow him off."

"Huh? But that's the whole point of the Seals. Three Seals were supposed to be enough to get through the island's barrier."

"'Enough' means that without the Seals, attempting to cross the barrier results in certain death."

Calra replied calmly.

"...Hold on. So what do the Seals actually do?"

"They take 'certain death' down to 'maybe you won't die.' That is about the extent of it."

"That's not what I was told at aaaall!?"

"We are taking off now."

The Dragon Emperor beat her dazzling wings.

Clamped firmly in Calra's forelimbs with no chance to resist, Ren took flight toward the Isle of the End.

Orperia Beach, after the Dragon Emperor's departure.

On the shore that should have been deserted, a blue-haired demon stood squinting up at the morning sun.

"......"

Exhaustion was etched deep into her features.

Her breathing was still ragged, and beads of sweat clung to her forehead. Too spent to even stand, the blue-haired demon — Housekeeper Lulu — sank to the ground where she stood.

Waves lapped at her ankles.

"I don't recall being on friendly terms with you."

Lulu, who had been staring at the water's surface, turned her gaze to the presence standing at her left.

"Goddess Resflaze. If you stand any closer, your divine aura is going to rub off on me."

"Don't be so cold. Consider this a special occasion."

A girl's voice, light and dismissive.

Beside Lulu on the sand stood an angel with the rarest of eyes — Odd Eyes.

Short, honey-colored hair that flicked outward at the tips. A childlike face. She looked about the same age as Elise, or perhaps a year or two older at most.

Eyes of endless, vivid azure.

And eyes that blazed with the color of seraphim-heaven.

Among all the contrasts of red and blue in this world, no pair of eyes held the sky's hues this deeply, this strikingly. There was only one such pair in all of existence.

Resflaze, Goddess of Heaven.

That was the name of the angel who bore those otherworldly eyes.

"I certainly did not expect you to crawl out of the Underworld."

"I did not expect to hear that from you. The goddess who never budged from Heaven — not even during the great war three hundred years ago."

"Times change, for both of us."

The Goddess spread something like a pale green lotus leaf on the sand and sat down cross-legged upon it.

"So? Worried about them, so you tagged along, First Demon King?"

"I merely wished to check on the replica's condition."

Glancing sideways at the Goddess who had settled beside her.

The demon once called the First Demon King wore a rare look of displeasure.

"And stop calling me that. I believe I told you that next time, I would not let it slide."

"Indeed. I've heard that about thirty times now."

Resflaze, meanwhile, gazed serenely toward the horizon.

"If it is a past you wish to forget, then rather than bristling at every mention, you would do better to cultivate the composure to laugh it off."

"That condescension of yours is grating."

"Forgive me. That may no longer be a habit — it may simply be who I am."

The girl with the Odd Eyes scooped up a handful of sand.

Watching the grains slip through the gaps between her fingers, she murmured with something like fondness.

"You cast aside the title of First Demon King, yet I still carry on as leader of the angels. That is the difference between us."

"You said it again..."

The blue-haired girl sighed with an exasperated tone.

"I'll let it go just this once. I believe I've also said that about thirty times."

"Mm."

The Goddess nodded — her expression unreadable, somewhere between jest and dead seriousness.

"The moment of truth, then."

"Just as it was three hundred years ago — entrusting everything to a single human. Demon, dragon, and angel alike."

"Yes. But there is one difference from three hundred years ago."

She paused.

Squinting against the sun rising over the horizon.

"He is not Eleline. He is neither the strongest nor invincible, and he cannot do everything alone. But in return —"

"He can speak with spirits. And if that is so, then perhaps —"

"Precisely."

To Lulu's words, the Goddess nodded with a wry, rueful smile.

"A shame, though. I would have liked to see it with my own eyes."

"What the Encore will tell him on that island... Yes. I would have liked to see that as well. I envy Elise."

With those words, the blue-haired demon rose to her feet.

She glanced down at the Goddess of Heaven, still seated — then turned away just as quickly.

"Leaving already?"

"It's time to give the dark fairies their assignments."

Housekeeper Lulu vanished, dissolving into the sunlight.

Watching her go, the girl with the honey-colored hair rose slowly to her feet as well.

"Hm. An earthly dawn. How nostalgic."

She cast one lingering glance at the horizon —

And then the Goddess Resflaze, too, was gone from the surface world.