Isekai Dungeon Architect

The first breath back in my physical body was like slamming into cold water.

"—ghhh!"

My lungs dragged in air, the nerves throughout my body familiarising themselves with the energy of my soul, while my knees buckled under the sudden weight of flesh again.

-Zup!

The violet gate behind us shimmered and then snapped shut with a hiss of mana, cutting me off from the association office on the other side. Riddle's sharp profile, the last thing that was reflected in my eyes, was gone. The rookies lined up in front and behind me in rows were gone too.

The safe hall of the Association, the sanctuary of safeness, had vanished as well.

Now, it was just me in this endless dungeon, oh, and him too.

"H-huh? Miss Aria? Are you alright?"

Cassiel stood beside me, pale hands clutching his too-tall staff, his throat bobbing as he swallowed. The faint shimmer of the gate's collapse still reflected in his wide eyes.

I pushed a hand against the wall to steady myself. For a heartbeat, I wondered if I had only imagined the spectral form.

The ghastly experience, that whole test, feeling and seeing the entirety of the dungeon with everything inside, I saw everything there was, but… was everything I saw true?

'I questioned myself.'

But then… There.

-Zaaaaaaa…

A faint glimmer traced across the stone wall on both sides. Hair-thin lines of light blue light pulsed gently, like veins beneath the skin.

Exactly like what I'd seen when floating above, these were the mana channels that sustained the entire dungeon and supplied energy throughout everything inside the dungeon from the dungeon's core.

This version was dimmer, blurrier, but it was still there, woven into the bones of the dungeon.

'So I can still see pieces of it… even like this.'

The dungeon's guest architect privileges were applied to my physical form as well, huh?

The thought made my lips twitch. It wasn't just a ghostly dream, then. My Architect's sight still worked, albeit with severe restrictions.

If I try getting back outside the same way I returned, would I enter the Spector form again?

'Hmm…'

I thought about it for a moment, but then just shook my head. It wasn't worth it. That experience wasn't something I could get used to so soon.

"Haaah…" Cassiel exhaled shakily beside me, figuring out I was fine on his own.

His grip on the staff trembled, though whether from fear or excitement, I couldn't tell. His delicate features were tense, his pretty face set like porcelain about to crack.

I straightened, brushing imaginary dust from my armor. "Well. That's that. Riddle won't be babysitting us anymore."

He blinked at me, startled. "She… stayed outside?"

If he was stalking me, he must have seen her with me ever since we came here. He knew exactly who she was, but perhaps not how important she was in this city.

"Mm. Proxies don't come in here. This test's on us." I tilted my head toward the deeper corridors. "Just you, me, and whatever's crawling in the dark."

My own words won me a nervous laugh. I had seen everything in this dungeon, I knew what kind of monsters were in here… and I swear I don't want to meet even a third of those things.

"Hmmm!"

He looked at me like I was far braver than I felt. Poor kid didn't know I was having an anxiety attack, debugging a freaking wall just a moment ago.

"Let's move," we started forward, boots echoing faintly across the stone.

The dungeon's air pressed cool against my skin, damp with the weight of mana. Every corridor seemed to breathe, and I would be lying if I said it was just my imagination.

The dungeon, as I had just confirmed, was a living entity. It was breathing, it was alive, it was watching.

It wasn't long before Cassiel spoke up, voice low, as though afraid something from behind the walls might overhear.

"Miss Aria… um. What kind of magic do you use?"

I blinked at him, then smirked. "Nosy, aren't you?"

'Did he think I was a spatial mage as well? How cute.'

His face colored instantly. "Ah! N-no! I just… You handled yourself so well in the practical test, I wanted to know—"

I shook my head, cutting him off with a lazy wave. "Trade secrets, cutie. You don't ask a girl what she's packing on the first date."

His mouth opened, then shut again. His blush reached his ears when he finished processing what I had just said.

"D-date?!"

Before he could combust, I leaned forward, eyes glinting. "But I'll tell you what. You show me your magic first. I want to see how you cast. I might just show you a thing or two, if I'm impressed."

"Eh?!" His grip on his staff tightened like I'd just asked him to strip. "M-my magic?"

"Mm-hm." I stepped closer, my grin sharper. "Come on, Cassiel. I want to learn from you. Show me how the pretty mage lights his sparks."

"Umm…"

Cassiel hesitated only a moment longer before he finally drew his staff upright.

-Oooooooooooong…

The carved wood was trembling faintly in his grip. His pale lashes lowered, his lips forming a quiet breath. He stayed quiet for a moment, but then lifted his staff.

-Shrrrrr…

The air shifted.

No words were spoken. No long-winded chant, no incantations whatsoever.

-Tap!

Just a single, sharp flick of intent. And…

The crystal head of his staff caught light as a flame bloomed at its tip like a newborn star.

"…Ohhh." My smile spread slowly and hungrily. "Incantation-less casting? Now that's sexy."

I had just learned that vibrations were needed in order to move the Mana in a stable environment. The vibrations were the chants and hand movements of the mages, but what this little guy did was completely different.

'What technique was this?'

I was curious, so I instinctively grabbed his hands.

His eyes darted up, startled, cheeks pinking. "I-it's nothing great! Just sparks. See?"

The flame fizzled down to a glowing ember as he demonstrated his magic, still no chant, no hand-sign, or any unnecessary theatrics.

From what I can tell, it was just his will. Just control over the elements he was connecting the Mana with.

In the eyes of others who are used to seeing chants and dramatic hand gestures, this silent chant may seem wrong. Some may even praise or criticise it.

But to me, it was beautiful. Precise, elegant, and something I wanted to learn as well.

I folded my arms, pretending to be unimpressed, even as my mind spun with calculation.

'He makes it look natural. Like flicking on a light switch. But I can see the mana pulling from inside him, the way his core threads through the staff, even the mind activation.'

There's Mana concentrated inside his head, something all the other mages have as well. But, unlike them, he is actually using that Mana.

Perhaps magic was connected more to the mind than I had figured out until now.

'Should I ask him how he just did that?'

That was when a thought tugged at the corner of my mind. No— not a thought, but a familiar voice.

[ "Observation complete. Do you wish to attempt recreation using {Creation}?" ]

My lips curved despite myself. "You always pop up at the right times, don't you?"

[ "The Assistance System exists to assist." ]

The voice I was going to name but forgot the moment I came back to my physical body, my system sister, chimed once again.