The screeches of demons tore through the air in all directions.
Demons clad in black armor packed the hallway, while bat-winged monsters hung densely from the ceiling. The floor was already slick with blood and crushed bones.
The Demon King knelt on one knee atop his shattered throne.
He was still breathing.
That was the most critical problem.
"Concentrate your firepower to the rear!"
The moment I shouted, the Elf Archer's arrow shot forward, glowing with light. Right after, I snapped off a brief chant.
Seca [Cutting]
Space warped as if folding in on itself.
The horde of demons split apart. Red blood and black flesh splattered against the walls, carving open a narrow path.
It was only for a fleeting instant.
"Run!"
Yet that was enough.
The Hero turned, gripping the Holy Sword. The Elf Archer bolted, practically carrying the Gnome Saintess in their arms. The Saintess continuously radiated healing light from her bloodstained hands, but her face was already deathly pale.
Everyone ran.
Except for one person.
"...?"
Sensing something amiss, the Hero looked back.
His eyes met mine.
"Kael!"
I chuckled at his uncharacteristically trembling voice.
I couldn't help but smile.
Otherwise, wouldn't I look like someone who stayed behind just to die?
"Go."
"What are you doing?!"
"Trust me."
I drove my staff into the ground.
Beneath the black marble floor of the Demon King's Castle, the magic formulas I had hidden spread out. Blue lines spiderwebbed across the surface, beginning to envelop the entire throne hall.
"We've survived this far somehow, haven't we?"
"Kael!"
"I have no intention of dying this time, either."
The Hero's face contorted.
The moment he tried to take a step toward me.
"If you stay, everyone dies."
I deliberately kept my voice cold.
The Hero froze for a moment at those words.
It seemed to have worked.
He gritted his teeth. Clenching the Holy Sword so hard his hands trembled, he finally turned around.
"Make sure you follow us!"
"Don't order me around. Since when were you my superior?"
The Hero didn't reply.
He merely kept his head down and ran.
Their figures vanished past the crumbling hallway.
Only then did I exhale a long breath.
"...Now then."
The demons swarmed in.
Wounded magical beasts began closing in on me, like predators fighting over the last remaining prey.
The Demon King raised his head.
A grin spread across his bloodstained face.
"Magician.... What can you possibly do alone?"
I looked at him.
How many people had died just to slay that monster?
The soldiers at the Northern Fortress who kept the gates open until the very end.
The priests who burned to death after ensuring the children evacuated first.
The combat engineers who destroyed the bridges and were buried alive just to delay the Demon King's Army by a single day.
And my master.
Even that foolish, kind-hearted old man who told me to survive until the end had died.
This was the only chance.
The Demon King was dying.
Yet he was still breathing.
This moment would never come again. And even if it did, how many more sacrifices would it demand?
The demons would crown a new king, or the Demon King would recover. The war wouldn't end. The continent would be soaked in blood for decades more.
Rather than witness that nightmare again, I would gladly stand at the center of the magic circle myself.
"You ask what I can do alone?"
Snap.
As I snapped my fingers, the entire throne hall lit up.
The floor, the pillars, the ceiling, the Demon King's throne, and even beneath the demons' feet.
Every formula I had inscribed since the moment I stepped into this castle awakened all at once.
"A magician's job has always been to overturn the battlefield single-handedly."
The Demon King's expression twisted.
"Don't tell me...."
"That's right."
I drew a small crystal from my robes.
The Teleport Coordinate Stone.
One linked beforehand to an escape point outside.
In theory, it was foolproof.
Just before the massive explosion, I escape using the coordinate stone. The Demon King and his demons vaporize alongside the hall. The Hero's party survives. The war ends.
What a clean, simple plan.
"Incineration Formula, deploy."
Blue flames flared up around me.
Starting near my heart deep within my body, mana surged along the circuits in a violent rampage.
Through my arms, legs, and all the way to the crown of my head.
The magic circuits engraved across my entire body began to unlock, one by one.
Under normal circumstances, I would never do this.
Because this was practically nothing short of a gamble.
I knew that better than anyone.
Yet right now, I had no choice.
This was the only chance to kill the Demon King.
If I let that bastard slip away, the war would ignite once more.
Countless lives would collapse, groaning in agony.
So.
I will kill him right here, once and for all.
Even if the price is never being able to cast magic again.
No.
Even if my magic circuits burn to ash right on this spot.
"Compress."
Mana was sucked toward the center of the throne hall.
At the same time, I felt something tearing inside me.
A portion of my magic circuits was surpassing its limit.
Agony, as if liquid fire were coursing through my veins, pierced my entire body. My fingertips trembled, and the edges of my vision blackened. Red blood trickled slowly from my eyes and mouth.
I clenched my teeth.
Without stopping, I forcibly unlocked the dormant circuits, one after another.
The first circuit.
The second circuit.
The third circuit.
I forcefully pushed even the deep-layer circuits that I would normally keep sealed.
The blue flames deepened.
The magic formulas blanketing the throne hall regained their light one by one. The lines on the floor spread to the pillars, and the lines on the pillars connected to the ceiling. The entire hall began to thrum.
The demons screamed.
Their bodies crumbled into ash before the flames could even touch them.
The mana structure sustaining their very existence collapsed from within.
The Demon King tried to haul himself up, but it was already too late.
The formula had already reached beneath his feet.
Every line and mark I had laid down from the moment I entered the castle.
All of it converged toward a single purpose.
To erase every single existence in this place.
Leaving nothing behind.
"Do you plan on dying with us?!"
The Demon King roared.
For the first time, fear laced his voice.
I gripped the coordinate stone in my robes.
My fingers lacked the strength to grip it properly.
I had opened too many magic circuits.
I couldn't guarantee I could even activate the teleportation.
A laugh slipped out.
And here I thought it was a foolproof plan in theory.
"No."
I said, exhaling a breath thick with blood.
"It's enough that only you lot die."
The Demon King's eyes blazed with fury.
- Kael Arvent!
The moment he roared my name.
I unsealed the final lock.
The core circuit bound deep beneath my heart.
The final pathway that even my master warned me never to open recklessly.
As that circuit unlocked, it felt as if the world had briefly ground to a halt.
Sound.
Heat.
Screams.
Everything faded into the distance.
In their place, a single light surged from within me.
All the mana I had accumulated until now.
Every last drop poured into a single formula.
With a final chant, I completed the formula.
Confringo [Explosive Chain]
The world turned white.
Even sound ceased to exist.
Heat, pain, light, and darkness tangled together in an instant.
..
..
"...."
An indescribable stench jolted me awake. My head throbbed.
It was probably the aftermath of mana exhaustion.
'Wait, what is this smell...?'
It wasn't the smell of blood or gunpowder; it was foul beyond belief.
Nor was it the sulfur and rotting flesh I had smelled beneath the Demon King's Castle.
Rotten food, grease, stale filth, and an unrecognizable odor blended together to assault my nose.
The stench was vile enough to be mistaken for the Demon King's curse, making me gag.
I forced my eyes open with great effort.
My blurry vision gradually cleared, and the surroundings came into view.
"...?"
I was struck speechless.
A rusted metal lid tilted halfway above me, and my body was shoved inside the bin. Behind my back, I felt something damp burst under my weight.
I slowly raised my hand.
An unidentified brown liquid trickled down between my fingers.
"Ugh...."
I hurriedly shook off the disgustingly sticky liquid.
"Where am I...?"
The coordinates I had set were definitely for a small village on the outskirts of the Demon King's Castle.
A place with low stone walls, a windmill, and an old well at the village entrance.
A safe zone where Leon, Aileen, and Miria were supposed to arrive.
But this wasn't that place.
Not by any stretch of the imagination.
Gripping the edge of the metal bin, I pulled myself up. A sudden wave of nausea churned my stomach. My legs gave out and I nearly collapsed back down, but I barely managed to keep my balance.
First, breathe.
Next, check my senses.
Sight, hearing, touch, and mana sensitivity.
A magician dies the moment they are swayed by emotions.
I immediately sank my consciousness into my body.
Magic circuits.
The pathways of pure mana that I had tempered all my life.
I had to confirm whether they were still intact.
After a moment, I let out a short breath.
They remained.
But naturally, they weren't unscathed.
"...At least it's not the worst."
I muttered quietly.
The circuits hadn't completely burned out.
In that case, I could recover.
Having dodged one crisis, I focused on my current situation.
'Coordinate error.'
Possibility one.
The mana turbulence right before the massive explosion warped the teleportation coordinates.
'Spatial interference.'
Possibility two.
The barrier lingering around the Demon King or the Demon King's Castle itself interfered with the teleportation formula.
'Temporal deviation.'
Possibility three.
The hypothesis I wanted to avoid most.
I raised my head and surveyed my surroundings.
It was a narrow alley.
It looked like masonry, but it wasn't natural stone.
Tap, tap.
When I tapped it lightly with my knuckles, a hollow resonance echoed back.
I didn't know its exact name, but I could tell its purpose.
A cheap, lightweight material ideal for rapid construction.
Unfit for the outer walls of a Magic Tower, yet perfect for stamping out an entire city in bulk.
Across the walls beyond the alley, blue glowing letters surfaced and vanished.
'Runic script?'
No, that wasn't it.
It looked like runes, but the flow of mana was shallow.
It was closer to a device programmed to repeatedly project fixed information with light.
'An illusion formula for display.'
Even if I didn't know the name, I could see the underlying principle.
The magic of this city differed from what I knew.
I placed my hand against the wall.
Cold.
A faint vibration resonated from deep inside the wall.
Mana was flowing through it.
However, it was not the natural flow of mana I was accustomed to.
Refined, fragmented, and standardized power.
Would it feel like this if mana were piped through plumbing like water?
'Is the entire city a single magic circle?'
Just then, a low roar reverberated from above the alley.
Whuuuum.
Reflexively, I looked up.
And once again, I was left speechless.
The sky was nowhere to be seen.
Or more accurately, far too many things blocked the sky.
Buildings towering on either side of the alley pierced through the clouds.
Castle towers couldn't even begin to compare.
Megastructures that looked like dozens of royal spires stacked atop one another reached toward the dark sky as if competing with one another.
It wasn't an impossible structure.
It was feasible with gravity reduction formulas and load distribution circuits.
The problem was that this had been applied not just to a single building, but to an entire city.
'There must be a dedicated mana power source.'
This wasn't at the level of individual magicians or noble families.
This city was drawing mana from a centralized source.
Some buildings glittered entirely like colossal crystal pillars.
Other buildings were clad in black metal, with golden circuits endlessly revolving along their surfaces.
Unfamiliar emblems hovered at their summits.
A winged gear.
A crystal eyeball.
A staff entwined with a serpent.
Each looked like the crest of a different noble house.
But something was off.
They weren't flags.
The crests floated in midair.
'Illusion magic?'
I furrowed my brow.
Then who on earth was squandering mana like this?
Constantly maintaining illusion magic just to show off a noble house's crest?
'Are they flaunting their wealth?'
Inside a track shaped like a transparent tube, a silver monster glided along.
I instinctively lowered my posture.
Because I had no way of knowing whether that thing was a living creature, a golem, or a siege engine.
Inside that silver monster, there were people.
Dozens of them.
No, hundreds.
They were sitting there casually.
'Is it a transport vehicle powered by a Levitation Formula?'
Below it, flying carriages—no, chunks of metal too absurd to even call carriages—streaked back and forth through the air.
Words glowed on the sides of their hulls.
[Archeon Genetics]
[Lumendyne Fuel]
[Seraph Industry]
I stared blankly at them.
Suspended between the buildings was a gigantic woman—or more precisely, the translucent upper body of one.
Half human and half mechanical apparatus. Smiling, she floated a small crystal vial above her palm.
Text flashed beneath her.
[Mana exhaustion, endure it no longer.]
[Legal Awakening Supplement, Aetherin.]
The corners of my mouth tightened.
'Treating mana exhaustion with pharmaceuticals?'
Pure nonsense.
The cause of mana exhaustion isn't just a lack of mana. It involves a tangle of complex factors, making it a taboo that no one should meddle with carelessly.
Yet that didn't mean it was completely impossible.
If it wasn't medicine to restore mana, but a stimulant forcibly squeezing out the residual mana left in the circuits, it might have a temporary effect.
Of course, the user's circuits would be ruined.
I gazed at the smiling woman in the illusion.
'That's not medicine, it's poison.'
A hollow laugh escaped me.
"What a crazy place."
But there was little time for awe.
First.
This is not the village I designated.
Second.
The surrounding environment differs from any city on the continent I lived on.
Third.
The level of magic engineering is abnormally high.
Fourth.
The atmospheric mana concentration is high, but its flow is artificially controlled.
Based solely on the facts confirmed so far, no known place fit the deductions.
At least in my mind.
And.
This is not the world I once knew.
It took a single day to accept that truth.
It took a month to accept that I might never be able to return.
And finally.
It took a year before I finally gave up struggling to return.