I roll my shoulders once, then crack my knuckles out of habit, the faint sound echoing just a little too clearly in the empty boss room. It lingers longer than it should, bouncing off the stone like the dungeon itself is listening.
"...Yeah, that's not ominous at all," I mutter under my breath, glancing around briefly before focusing forward again.
The throne is gone—reduced to rubble—and what it hid is now fully exposed.
A structure.
Not large, not imposing, and definitely not something that would stand out if you weren't already suspicious. If anything, it looks deliberately unremarkable, like it was designed to be ignored.
Which, in this case, makes it worse.
I step closer, narrowing my eyes slightly as I take in the details, my gaze moving from the center outward.
"Of course," I say quietly, tilting my head. "Because hiding something suspicious behind something obvious wasn't subtle enough."
At the center sits a small totem-like construct, its surface etched with thin, deliberate lines that pulse faintly with mana. The glow is controlled, steady—not wild, not unstable.
Organized.
That alone is a problem.
"You're neat," I mutter, crouching slightly. "I don't like neat."
At the top, embedded cleanly into the structure, is the dungeon core—or something functioning like one. From it, four narrow conduits extend outward, each connecting to a separate tower placed at equal distance around the center.
Each one hums softly, each one active, and all of them feeding into the core in a steady, synchronized rhythm that feels far too deliberate to be accidental.
I exhale slowly as I lower myself just enough to align my view with the core's pulse, watching the way the energy cycles through the system before returning to its origin point.
"So that's why the core didn't show up," I say, more to confirm my own thoughts than anything else. "It never left in the first place... which, honestly, is already annoying."
The core isn't missing—it's being used.
I extend my senses carefully this time, letting my mana brush against the structure without forcing it, like tapping lightly on glass just to see what responds on the other side.
Demonic in nature, faint in presence, but completely unmistakable once you know what you're looking for.
"Great," I sigh, closing my eyes briefly. "Because of course it's demonic. Why wouldn't it be at this point?"
At first, the conclusion seems simple. The core is being drained, its energy siphoned outward through the towers in a slow but steady extraction process. It's inefficient, sure, but effective enough if left alone long enough.
"Standard parasitic setup," I mutter, tilting my head slightly as I observe the flow. "Ugly, inefficient, and honestly kind of lazy... but it works if you're patient."
I almost leave it at that, ready to move on with the assumption.
Almost.
Then something doesn't sit right.
I lean in slightly, focusing harder—not just on the direction of the flow, but on its behavior, its consistency, the way it cycles instead of diminishes.
The output isn't dropping.
It's rising.
I blink once, then straighten slowly, my expression shifting as the realization starts to settle.
"...No," I say quietly, more to myself than anything else. "That's not right."
The pulse strengthens again—not dramatically, not violently, but with a steady, controlled increase that repeats just enough to confirm it isn't random.
"You've got to be kidding me," I mutter, dragging a hand down my face as I reassess everything. "You're not draining it..."
I look back at the towers, then the core, then back again, letting the pattern lock into place.
"You're feeding it," I finish.
I let out a longer breath this time, the entire situation rearranging itself in my head as the correct structure becomes obvious.
"So it's not a parasite," I say slowly, "it's a pump—an amplifier, something designed to continuously reinforce the core instead of weakening it."
I pause, then glance toward where the boss should have been, the absence now feeling significantly less reassuring than it did earlier.
"Which raises a much more annoying question," I continue, tilting my head slightly as I think it through. "If the core is still here... then how exactly did the boss respawn?"
There's only one answer to that.
And I already don't like it.
I turn back toward the core just as the pulse spikes again—not dramatically, but just enough to signal that something is about to happen.
"...Right on time," I say flatly, already bracing for the next problem.
The core lifts slowly and deliberately, as if responding to an unseen command, while the air around it tightens and condenses with gathering mana. The space itself begins to distort slightly, like something is being forced through a gap that shouldn't exist in the first place.
I don't move.
I just watch, because at this point there's no reason not to.
"Of course," I sigh. "Because one problem clearly wasn't enough for today."
The manifestation completes.
And what stands before me is—
I pause, narrowing my eyes slightly before tilting my head.
"...That's not an Ogre King," I say, the realization settling in almost immediately.
The creature is massive, its body formed from dense, stone-like material reinforced with glowing veins of mana. Its frame is exaggerated—broad shoulders, elongated limbs, and a core embedded deep within its chest, pulsing in sync with the totem behind it.
"A Titan Guardian," I add, straightening slightly. "And an upgraded one, too."
I exhale through my nose.
"That's an A-rank boss," I say, mostly for confirmation. "Inside a dungeon that shouldn't even support it."
I rub the back of my neck.
"...Yeah, no. We're not dragging this out," I decide.
The Titan moves.
Slow at first.
Then suddenly far too fast for something that size.
I don't step back immediately. Instead, I watch, tracking the mana flow through its limbs, noting how the totem reinforces each movement.
"External supply, internal reinforcement," I mutter. "So you're borrowing strength instead of generating it."
The Titan's arm swings down.
"Spatial Interference," I say calmly.
The trajectory bends slightly—just enough. The strike misses me by inches, slamming into the ground with a force that fractures the stone beneath us.
I step aside lightly.
"You're strong," I add, "but you're predictable."
The Titan roars and lunges again.
"Alright, fine," I sigh. "Let's speed this up."
"Void Step."
My presence flickers out for a fraction of a second before reappearing several meters away. The Titan overshoots, momentum carrying it forward.
"Too straightforward," I comment.
I raise my hand.
"Mana Disruption."
A pulse spreads outward, targeting the connection between the Titan and the totem. The glowing veins flicker, the flow stuttering.
"There it is," I say, watching the disruption take hold as the flow between the Titan and the totem stutters visibly. "That's your weak point—external supply. You rely on it too much."
The Titan hesitates for just a fraction of a second, its movement desynchronizing as the mana feeding into it falters.
That's enough.
"Arcane Chains," I say, lifting my hand slightly as the spell takes form.
Bindings snap into place around its limbs and torso, not fully restraining it but applying just enough pressure to interrupt its balance and delay its response. The Titan immediately strains against them, cracks forming along its surface as it tries to force its way free.
"You're strong," I admit, watching the structural stress build, "but you're not efficiently designed. Too much reliance on reinforcement, not enough internal stability."
I shift my fingers slightly, adjusting the flow.
"Elemental Override," I continue, voice steady.
The mana feeding into the Titan twists under my control, its structure forcibly rewritten as reinforcement collapses inward and turns against itself. What once supported its frame now destabilizes it from within, exposing the core embedded in its chest.
I don't rush. I never rush, because rushing introduces error, and error is unnecessary here.
"Arcane Lance," I say quietly, already knowing the outcome.
The construct forms instantly—thin, precise, and absolute—before launching forward with controlled force, piercing straight through the exposed core without resistance.
The Titan freezes mid-motion as the impact registers.
Then the cracks spread.
Then its entire form collapses, breaking apart into fragments of fading mana that scatter across the floor before dissolving into nothing.
Silence settles over the room again.
I lower my hand slowly, exhaling lightly as the tension fades from the space. "...Done," I say, more out of habit than necessity.
That wasn't difficult. It was simply inconvenient—something that required attention, not effort.
I walk forward and begin collecting the remaining materials, crouching slightly as I pick up the denser fragments and core remnants that haven't fully dissipated, storing them away without much thought.
"Might as well," I mutter, because leaving resources behind is a waste, even if the situation itself was unnecessary.
Once I'm done, I straighten and turn my attention back to the totem.
It's still active. Still pulsing. Still functioning like nothing just happened.
"Yeah," I say, narrowing my eyes slightly. "We're not leaving that behind."
I step closer without hesitation this time, already deciding how this ends.
"Arcane Resonance—Disintegration," I say, letting the spell take hold immediately.
The structure trembles as cracks spread rapidly across its surface, the lines of mana fracturing as the system destabilizes from within. The towers flicker in sequence before collapsing entirely, their glow fading as the connections break one by one.
At the center, the core shatters—not violently, not explosively, but cleanly, like it was never meant to exist in the first place.
Gone.
The dungeon responds immediately as the system collapses. The air shifts, the structure destabilizes, and the faint hum that filled the space disappears entirely, leaving behind a hollow stillness.
I straighten, rolling my shoulders once as the tension finally fades from the environment.
"That should do it," I say, stretching slightly before letting my arms fall back to my sides.
I glance around one last time, making sure there's nothing left reacting, nothing hidden, nothing waiting to become another problem.
"I'll have Ruruka report this," I add, already deciding how little involvement I intend to have with the aftermath. "Let the guild deal with the rest."
Because I'm not doing paperwork.
Not today.
I take one final look around the room—no movement, no anomalies, no surprises—before nodding slightly to myself.
Good.
"Alright," I say, turning toward the exit. "Time to go home."
As I start walking, I can already feel the contrast between this place and what's waiting for me outside, and for a brief moment, I find myself genuinely considering the difference.
Because somehow... I'd rather deal with three chaotic children than whatever this was.
And honestly, that says a lot.
***
By the time I return to the apartment, I already have a feeling something went wrong.
Not a dramatic kind of wrong. Nothing explosive, nothing catastrophic. Just… the kind of wrong that quietly builds up when you leave three highly energetic children in one place, even under supervision. The kind of wrong that doesn't announce itself—but waits patiently behind a door, ready to greet you the moment you open it.
Still, I tell myself it's probably manageable.
That assumption lasts exactly three seconds after I open the door.
Ruruka is on the floor.
Flat.
Completely defeated.
For a moment, I don't even step inside. I just stand there, one hand still on the doorknob, staring at the scene like my brain is trying to decide whether this is real or some kind of elaborate illusion spell I accidentally walked into.
Hikari is sitting on her stomach like it's the most natural seat in the world, legs neatly tucked, posture perfect, like she's attending a formal gathering instead of committing what is technically assault.
Karin is attempting some kind of leg lock that is far more enthusiastic than it is technically correct, her expression shining with the confidence of someone who clearly has no idea what she's doing—but is convinced she's a prodigy.
And Ruri—who is clearly doing her best—is trying to separate them with the determination of someone who has already accepted failure as a likely outcome.
…Yeah. That checks out.
I close the door behind me slowly.
"...Ruruka," I say, voice completely flat, "what exactly happened here?"
Karin looks up immediately, grinning like she just achieved something impressive.
"I was testing a new secret technique," she says proudly, as if that explains everything.
Of course you were.
Of course that sentence exists in my life now.
Before I can respond, Hikari raises her hand like she's presenting a report.
"Hikari will explain," she says, very serious, very composed. "We were watching anime. Then Hikari woke up. Then we watched together. Then Karin asked Auntie about fighting. Then Auntie explained. Then Karin tried it."
She pauses, as if reviewing her own summary for accuracy.
"And now we are here."
I blink once.
That was… surprisingly structured. Disturbingly logical. If I ignore the outcome entirely, that was actually a very efficient report.
I glance at Ruruka.
She doesn't move.
She just stares at the ceiling like she's questioning every life choice that led to this moment—starting from becoming a hunter, all the way down to agreeing to babysit.
"I see," I say.
I don't, actually.
But I understand enough to know I don't want further details.
I rub my temple briefly, feeling the beginnings of a headache forming—not from the dungeon, not from the Titan Guardian, but from this. This is what gets me.
"Alright," I say, shifting my attention back to the three of them. "Your aunt and I need to talk. Go sit down, behave, and watch your anime like normal people."
"But Papa! We're playing!" Karin protests immediately, clearly offended that her… whatever this is… is being interrupted.
"You're not playing," I reply calmly. "You're dismantling your aunt."
"That's part of playing!"
"No," I say, completely unfazed. "That's part of losing your babysitting privileges."
That lands.
Ruri gently pulls Karin back with quiet efficiency. "You're being a nuisance," she says softly. "Papa told us to behave."
Karin pouts, clearly offended, cheeks puffing slightly. "…Party pooper," she mutters, but she lets herself be dragged away anyway.
Hikari follows without complaint, sliding off Ruruka like none of this was unusual and walking toward the couch with the same calm composure she always has.
Ruri joins them, making sure Karin actually stays seated this time.
I let out a quiet breath and reach out, ruffling Ruri's hair as she passes.
"Thank you," I say.
She smiles, soft and genuine. "You're welcome, Papa."
…Yeah.
This child is the only thing holding everything together.
If she ever decides to join the chaos instead of managing it, I'm finished.
Behind me, Ruruka finally moves.
She sits up slowly, like someone returning from the brink of death, dusts herself off, then gestures toward the dining table.
"We need to talk," she says.
"Agreed."
We move to the dining table. She doesn't even ask—just heads straight to the kitchen, prepares coffee with practiced familiarity, and places a cup in front of me before sitting down across from me.
I glance briefly toward the living room.
The three of them are already fully immersed in the anime again.
Like the last few minutes didn't happen.
Like Ruruka wasn't just used as a training dummy.
"…They recover fast," I mutter.
"That's one way to put it," Ruruka replies dryly, taking a sip of her coffee.
I take mine as well, letting the warmth settle me before starting.
"The dungeon was normal at first glance," I begin, this time not rushing it. "Structure, layout, everything was consistent with a standard labyrinth. If you didn't look closely, you wouldn't notice anything wrong."
Ruruka nods slightly, her posture shifting into full focus now.
"But there were no monsters," I continue. "Not a single one. That's where it started to feel off."
Her expression tightens immediately. "None at all?"
"None," I confirm. "Even after a raid, something should be left. Residual presence, stragglers… anything. But there was nothing. It was too clean."
Too empty.
Like something had been deliberately cleared out.
I take another sip before continuing.
"So I checked the entire layout using spatial awareness. Every corridor, every chamber—mapped, traced, and double-checked. I didn't just skim it either. I ran it once, then again, then a third time just to confirm I wasn't overlooking something obvious.
Still nothing.
No monsters. No movement. No presence.
Just traces.
"Traces?"
"Mana residue," I explain, taking a bit more time this time instead of brushing past it. "Faint. Inconsistent. Not the kind you get from natural dungeon inhabitants. Those leave patterns—predictable, repeatable signatures. This was… scattered. Like something existed there temporarily and then got erased before it could stabilize."
I pause, tapping the side of my cup lightly.
"Think of it like footprints," I add. "Normal ones leave depth—you can tell what passed through. This? It's like someone stepped there and then smoothed the ground over right after. You know something was there… but you can't trace it."
Her brows furrow more deeply.
"That's when I went to the boss room," I continue, keeping the flow steady.
"And?"
"It was empty," I say. "No corpse. No core. No lingering pressure from a high-rank entity. Just a throne."
I glance at her briefly.
"And it was too clean. No damage, no mana distortion, nothing to suggest a fight ever happened there."
She frowns. "That doesn't match what I saw."
"Exactly," I reply. "Which is why the throne stood out."
I lean back slightly.
"It wasn't decoration. It was placed too deliberately—centered, reinforced, and more importantly… anchored."
I tap the table once.
"So I broke it."
She doesn't react.
She's used to it.
…Probably more than she should be.
"Behind it was a structure," I continue. "Not debris. Not a hidden compartment. A system. A totem connected to four towers—like a stabilizing frame. And the core wasn't hidden… it was integrated into it."
Her eyes narrow slightly. "So the core wasn't missing."
"It never left," I say. "It was embedded into a secondary mechanism—something designed to regulate or alter its function."
I pause briefly, organizing the thought more clearly instead of rushing ahead.
"At first, I thought it was being drained," I add. "That would've been the logical conclusion. Energy redirection, forced evolution—those are known irregularities."
She nods. "Right."
"But it wasn't," I say, quieter this time.
She leans forward slightly. "Then what?"
"It was being amplified," I answer. "Not redirected. Not consumed. Enhanced. Stabilized beyond its natural output."
That lands harder.
I continue without breaking the flow.
"I went in expecting an irregularity—maybe an evolved Orc King. Something that grew stronger due to excess mana. That still follows the system."
I shake my head slightly.
"But what appeared wasn't growth," I say, setting my cup down. "It was replacement."
She looks at me.
"A Titan Guardian."
She straightens immediately. "That's an A-rank entity."
"Exactly," I reply. "And that's the issue. Evolution increases capacity—it doesn't rewrite species. You don't jump from an Orc-type lineage to a Titan-class construct without bypassing the system entirely."
I lean back, exhaling slowly.
"So I stopped thinking in terms of evolution," I continue. "And started thinking in terms of interference."
She raises an eyebrow. "You?"
"You don't trust me at all, do you?"
"Not even a little."
…Fair.
I sigh, then continue more deliberately.
"The core I destroyed wasn't the original core of that dungeon."
Her confusion is immediate.
"That doesn't make sense," she says.
"I know," I reply. "Because everything we know about dungeons is based on the assumption that the core is fixed—singular and irreplaceable. Remove it, and the dungeon collapses. That's the rule."
I tap the table slowly.
"But what I saw contradicts that."
I lean forward slightly.
"That structure wasn't just holding the core—it was interfacing with it. Regulating output. Stabilizing fluctuations. Possibly even masking its signature. That's not something you build unless you're trying to override how the dungeon naturally behaves."
I glance at her.
"So either that core wasn't the original…"
I let the thought hang briefly.
"…or the system allows replacement—and no one's successfully done it until now."
Her expression tightens as she processes it.
"All we know is that dungeons require a core—that's the general truth," I continue, more fluid now. "But that's based on observation, not full understanding. We've never tested what happens if you introduce another core… or replace one mid-cycle."
I tilt my head slightly.
"What if a dungeon doesn't care about the 'original'—only that a valid core exists?"
I pause.
"What if you can swap it… and the dungeon just continues functioning like nothing happened?"
I pause for a moment, then add more quietly,
"And what if it doesn't stop at one?"
Her eyes narrow slightly.
"What if a dungeon could hold more than one core at the same time?"
She processes that slowly.
"That actually makes sense," she admits, though there's hesitation now.
I nod once.
"Which means someone didn't just interfere with the dungeon," I add, my tone more serious now. "They prepared it—set it up in advance, controlled the flow, and replaced parts of the system without triggering a collapse."
Her eyes narrow.
"Wait," she says. "If that core wasn't the original… then how do you explain the Orc King I fought?"
I pause.
Because that part matters.
I lean back, folding my arms loosely, thinking it through again instead of brushing past it.
"…Most likely a replica," I say.
"A replica?"
"Yeah," I nod. "If someone had enough mana crystals and the right materials, it's not impossible to construct a functional organism using mana structuring and controlled biochemistry. It wouldn't be perfect—but it would be convincing."
She thinks about it.
"…Now that I think about it," she says slowly, "it did feel weaker than expected. I thought I just overestimated it."
"You didn't," I say. "A replica wouldn't have the same density, stability, or internal structure. It mimics behavior—but not essence."
She pauses again, then adds—
"Also… I forgot to mention this earlier. It didn't drop anything. No materials, no core fragments—nothing. It just disappeared."
I glance at her briefly.
Then nod once.
"That confirms it," I say. "A constructed entity wouldn't produce proper drops. There's no real system binding behind it—just a temporary framework held together by mana."
I exhale quietly, letting the weight of the conclusion settle instead of brushing past it.
"So what you fought wasn't the dungeon's original boss," I say, more evenly this time. "It was a placeholder. Something meant to occupy the role… not fulfill it."
"A decoy," she mutters.
"Exactly."
I tap my finger lightly against the cup, gaze lowering for a brief second.
"A controlled variable," I add. "Something predictable. Disposable. Replaceable."
Silence settles between us, heavier this time—not empty, but filled with the implications neither of us feels like saying out loud.
Then—
"That's… worse," she says.
"Yeah," I reply, leaning back slightly. "Because it means whoever did this isn't experimenting blindly. They understand dungeon systems well enough to manipulate them without triggering collapse protocols… and confident enough to do it in a live environment."
Which means they're either insane…
…or worse, competent.
I don't like either option.
She studies me for a second, like she's trying to decide whether I'm overthinking it or not. Then her expression eases just slightly, the tension bleeding out of her shoulders.
"You're surprisingly efficient today," she says.
I take another sip of my coffee, unfazed.
"Don't get used to it," I reply, taking another sip. "This is me on a rare day where things make sense. I'm still aiming for doing less—preferably nothing—but apparently that's not an option anymore."
"Mm," she hums, amused, then gestures toward the living room. "With those three? That's not happening."
I follow her gaze toward the couch. Karin is leaning too close to the screen, completely absorbed, Hikari is correcting something she said with her usual calm seriousness, and Ruri is, as expected, keeping the two from turning it into another disaster.
…Yeah. That sounds about right.
I glance back at Ruruka and let out a small breath. "No arguments here," I mutter, more out of acceptance than complaint.
She lets out a quiet laugh, finishes her coffee, and stands, placing the cup down with a soft clink. "I'll report this to the guild," she says. "Since I know you won't."
"Correct," I reply immediately. Paperwork is a greater threat than any dungeon.
She walks toward the door, pausing just long enough to wave at the three of them.
"Bye, Auntie!" Karin calls out without looking away,
"Come back soon!" Hikari adds.
"Take care," Ruri says politely, as always.
Ruruka smiles faintly, then glances back at me. "Catch up later, Nii-sama."
"Take care," I reply, giving a small nod. "Call me if something comes up… or if it doesn't. Either way, I'll pretend I'm busy before deciding whether to help."
She nods once and leaves, the door closing with a soft click behind her.
The apartment goes quiet.
Not peaceful—just quiet enough to feel temporary, like something is about to break the silence any second.
I stand there for a moment, looking at the door before turning toward the living room. Three pairs of eyes meet mine immediately—bright, curious, and already full of energy I know I'll have to deal with.
We just look at each other for a second, no one speaking.
Then Karin grins.
…Yeah. That's never a good sign.
I let out a slow breath, already bracing myself. "...Right," I mutter under my breath. I'm not alone anymore—far from it—and somehow...
This is more exhausting than anything the dungeon threw at me.
*****
End of Chapter 13
RETIREMENT STATUS REPORT:
Owner: Ren Arclight
Former Occupation: Demon King Slayer / World-Saving Archmage
Current Occupation: Investigator of System-Level Anomalies
Peaceful Life Goal:
Avoid responsibility, avoid danger, and maintain a stable, low-cost lifestyle.
Today's Activities:
*Entered sealed C-rank dungeon solo
*Detected complete ecosystem suppression
*Confirmed absence of natural monster activity
*Located concealed structure behind boss chamber
*Identified artificial core interface system
*Observed core amplification instead of depletion
*Triggered unauthorized boss manifestation
*Engaged and eliminated A-rank Titan Guardian
*Confirmed external mana reinforcement system
*Destroyed artificial core and support structures
*Collapsed dungeon safely (minimal effort)
*Returned home expecting peace (critical error)
*Found sister defeated by children
New Developments:
*Dungeon core can be externally modified or replaced
*Multiple-core theory now viable
*Artificial boss entities can be constructed (replica-type)
*Dungeon system can be bypassed without collapse
*Unknown entity demonstrates advanced system knowledge
*Presence of controlled variables confirmed
*Threat classification exceeds standard dungeon logic
Household Status:
Supervisor (Temporary): Ruruka Arclight – Defeated
Children Status:
*Karin – Developing combat instincts (high aggression)
*Ruri – Maintaining structural stability (critical asset)
*Hikari – Demonstrating unpredictable interaction patterns
Peaceful Retirement Stability:
100% Before Doorbell
0% Dragons Hatched
–9000% Financial Stability
–30000% Dungeon Exposure
–60000% Guild Involvement
–100000% Dungeon Destruction
–200000% System Anomaly Encounter
–350000% Reality Rule Violation
–500000% Children Training Aunt Instead
Current Retirement Status:
Completely Irrecoverable
Immediate Consequences:
*Guild investigation pending
*Unknown entity remains unidentified
*Potential repeat anomalies likely
*Increased risk of higher-rank dungeon interference
*Household chaos scaling upward
Operational Assessment:
Mission Outcome: Successful
System Integrity: Compromised
Execution Quality: Efficient
Situation Complexity: Escalating
Emotional Status:
Suspicion - Realization - Mild Annoyance - Acceptance
Future Outlook:
Unstable
Archmage Personal Statement:
"I just wanted a quiet life. Now I'm debugging dungeons."
Reality's Response:
"New issue detected. Please investigate further."