(Shirou POV)
Boarding the train, I looked at Iroha and Ai.
"Take care, you two," I said, waving my hand at them. The two did the same until the doors closed.
The three babies were sleeping peacefully, and it had already been confirmed that Kaguya wasn't a threat. I'll get off at the next station and head back to enter the dungeon.
Who would have expected that I would encounter it at the mall. But then again, in the world of the Moonlit World, expect the unexpected. Who knows, you might slip on the road and end up waking in the Root.
Though I doubt Alaya and Gaia would like that.
Stepping out of the train, I walked to the opposite platform and waited for another train to head back.
"Maybe I can just sprint back there," I muttered, looking in the direction of my destination.
If only I knew how to use a Bounded Field properly, I could apply it to myself and sprint there without attracting attention.
"Senpai?"
While I was lost in my thoughts, I suddenly heard a voice behind me. When I turned around, I saw someone familiar.
Smiling, I looked at her. "Oh, Sakura. I'm surprised to see you here."
Sakura Edelfelt, the little sister of Rin Tohsaka, was adopted by the head of the Edelfelt family due to certain circumstances.
She gave me a warm smile. "I'm on my way to pick up my big sister."
My eyes widened in surprise because that could only mean one thing.
Rin was going home.
"I didn't know she was coming back today," I said.
Sakura tilted her head slightly. "She finished what she needed to do in London earlier than expected. She said she would return this afternoon."
"Is Luvia going back too?" I asked. The two of them were my childhood friends, and it was always entertaining to watch their rivalry.
"Yes." She nodded, then asked, "Are you heading home, Senpai?"
I hesitated for a second.
Going home. Technically, yes. But first, there was something I needed to take care of.
"Not yet," I replied. "I have something to check first."
Sakura blinked but did not pry. That was just like her. She would notice something was off, yet she would not push unless it truly concerned her.
"I see," she said softly. "Please be careful then."
"I will," I answered.
I still need to fix my soul so my memories can return. Now that I think about it, if I level up, will the damage to my soul start to heal?
It might.
If that happens, I need to leave the dungeon the moment I level up. If my memories suddenly return, even partially, I might lower my guard at the wrong time.
Although a dungeon appearing inside a mall was not something trivial. In a normal world, it would have caused chaos. But in the Moonlit World, strange phenomena tended to hide behind layers of mystery, unnoticed by ordinary people.
Any magus would love to have a field trip inside that dungeon. But I doubt they even have the ability to enter it.
Still, that did not mean the dungeon was harmless.
The train arrived with a metallic screech, interrupting my thoughts. The doors slid open.
Sakura stepped inside first, then turned back to me.
"Can I join your family for dinner?" she asked. There was a hint of hope in her voice.
I smiled. "Yeah. You're always welcome at our home."
She nodded, satisfied with that answer. "Then I will invite my two big sisters. Iris-nee would love to interrogate the two."
Before I could say anything, the doors closed and the train pulled away.
I watched it disappear down the tracks before exhaling slowly.
A few seconds passed.
"Ah, I got left behind by the train." The realization hit me, and I facepalmed. "Oh well. It's not like I'm in a hurry."
"I also forgot about the laptop in Iroha apartment." I muttered and contact Iroha about my things that I will get back later.
Then hearing another train approaching, I couldn't help but frown.
A train had just passed a second ago, yet another one was already arriving.
That's too fast.
The metallic screech of the wheels echoed across the station, sharper than before. I stared at the incoming train as it slowly came to a stop in front of me.
When the doors slid open with a mechanical hiss, no one came out.
No one was inside and every seat was empty.
There's no passengers, no conductor, no sound.
It was eerily silent.
Not the normal kind of silence, but the heavy kind that made the air feel thicker.
A translucent window suddenly appeared in front of me.
[You have successfully encountered the Train Dungeon.]
[Train Dungeon Level 1 – ∞]
[Do you want to enter the Train Dungeon?]
[Yes/No]
"…Infinite?" What kind of dungeon has an infinite level limit?
The first dungeon I encountered have a clear structure. Floors. Bosses. Endpoints.
But infinity?
That sounded less like a challenge and more like a trap.
This dungeon looked extremely suspicious.
I was shocked. This was the second time I had encountered something like this.
Still, my curiosity won.
Ignoring the infinite level warning, I pressed the Yes button.
The invisible barrier that had been preventing me from stepping forward disappeared instantly.
The moment I stepped inside, the temperature dropped slightly.
The doors closed behind me.
The sound echoed louder than it should have.
Then the train started moving, I glanced outside the window.
There were no tracks and the platform was gone.
There's only darkness that remained beyond the glass, endless and silent.
A new notification appeared.
[You have successfully entered the Train Dungeon.]
[You are now in the 1st Trial of the Dungeon.]
I narrowed my eyes, so this dungeon is the trial type?.
The lights flickered once before stabilizing, and then I saw her.
A woman with long white hair stood at the end of the carriage. A yellow glowing visor covered her eyes, glowing faintly in the dim light.
A system window appeared.
[Jun-Ninja: Level 5]
[Description: A humanoid close-combat unit designed for high-speed assaults. Specializes in blade-type attacks and relentless offensive pressure. Classified as a non-human entity. Eliminates targets without hesitation.]
She didn't have arms.
From her shoulders extended long, curved blades instead of hands, polished steel reflecting the pale light above us. My Mind's Eye immediately sent a warning signal. Her skin was unnaturally pale, almost paper-white.
She wasn't human.
She looked like a living corpse given mechanical precision.
As if responding to my killing intent, she lowered her stance and crossed her blade-arms in front of her body.
My instincts flared.
"Trigger-On."
Blue circuits manifested beneath my skin, glowing faintly through my veins. When I repeatedly used Trace-On yesterday, it leveled up and granted me a new skill: Trigger-On. Along with it came another ability called Sword Barrel.
Trigger-On synchronizes Trace-On, Magic Circuit activation, and Reinforcement into a single streamlined process. Instead of activating each separately, it compresses them into one efficient trigger, reducing prana leakage while boosting output stability.
Sword Barrel, on the other hand, is pure offense. It allows me to consecutively fire projected swords, consuming my mana capacity in exchange for overwhelming pressure.
The Jun-Ninja suddenly vanished.
Fast.
"Trace-On."
Predicting her trajectory through subtle air shifts and sound displacement, dual blades manifested in my hands.
Kanshou and Byakuya.
One black. One white.
A paired set of short swords forged as conceptual twins. Individually, they are B-rank Noble Phantasms. Together, their true strength lies in their resonance.
They are designed to be thrown and recalled. When one is launched, the other will curve unnaturally to follow its partner, correcting its trajectory midair as if bound by fate. Against non-human entities and corrupted beings, their compatibility increases, amplifying damage through their anti-evil properties.
Perfect for something that isn't human.
The Jun-Ninja reappeared directly in front of me, blades slashing downward in an X-shaped arc.
I crossed Kanshou and Byakuya to block.
Clang—
Sparks erupted on impact. The force pushed me back several steps, my shoes scraping against the train floor.
Strong.
For a Level 5 mob, her physical output was abnormally high.
I was lucky my Tracing level had improved. If it hadn't, Kanshou and Byakuya wouldn't have been able to shield me from that attack.
Sweat formed on my forehead.
And this is only the first trial.
For some reason, something inside me whispered that this wasn't the first time I had fought a creature like this.
She pressed forward without hesitation, her blade-arms spinning in rapid succession. Each strike was precise, mechanical, optimized purely for killing. No wasted movement. No hesitation.
I deflected one strike, sidestepped another, then twisted my body and slashed diagonally across her torso.
The blade connected.
But instead of blood, metallic sparks burst out.
"So she's reinforced."
No.
My Mind's Eye rejected that conclusion immediately. She wasn't reinforced.
She was naturally constructed that way.
Her entire body was a weapon. Dense. Hardened. Engineered for combat from the inside out.
If brute force won't work, then I need something with defense penetration properties.
She retaliated instantly, one blade thrusting toward my throat. I tilted my head just enough for it to graze past my cheek, leaving a shallow cut.
Fast.
If I fight her purely in close combat, this will turn into a stamina battle.
And I don't know how long this "infinite" dungeon intends to drag this out.
I exhaled slowly.
"Let's test something."
Prana surged through my circuits.
"Sword Barrel."
Behind me, multiple points of light formed in a semi-circular array. Projected swords materialized one after another, their forms stabilizing midair.
Instead of aiming to pierce her, I maximized their durability and output stability.
"Fire."
The swords launched simultaneously.
She crossed her blade-arms and began deflecting them with terrifying precision. Sparks filled the narrow carriage as steel collided with steel.
Good.
That's exactly what I wanted.
The barrage forced her into a defensive pattern, locking her in place for a few precious seconds.
Buying time.
I closed my eyes briefly and began a chant, stabilizing the projection formula.
"I am the bone of my sword."
The words weren't just symbolic. They aligned my internal world with the concept of weapon creation, increasing the quality of the projection.
"Steel is my body, and fire is my blood."
A significant portion of my mana drained instantly. My circuits heated up, blue lines glowing brighter beneath my skin.
What I need isn't raw power.
I need absolute penetration.
In my mind, I traced the structure of a crimson spear.
A weapon designed not to cut, but to reverse causality itself.
Gáe Bolg.
A barbed spear of cursed red, its true ability not merely physical. Instead of the spear piercing the heart because it was thrown, the heart is pierced because the spear has already determined the result.
Cause and effect inverted.
Against a target, it declares: the heart will be pierced.
Everything else follows.
"Trace… On."
The crimson spear materialized in my hand, its surface etched with ancient patterns. The air around it felt distorted, as if space itself rejected its existence.
My mana plummeted dangerously.
For a moment, even the Jun-Ninja paused, as if sensing the abnormality.
"This ends here."
I shifted my stance and aimed the spear directly at her core.
"Gáe Bolg."
I thrust forward, not aiming for her armor or her blades, but for the concept of her heart.
The spear didn't fly in a flashy arc. It simply appeared directly at her heart and thrust forward.
For a split second, nothing happened.
Then her body froze. She remained locked in place, but she wasn't moving anymore.
A crack appeared along her pale skin, scattering into tiny blue particles. A red light burst from her chest, as if something detonated within. The visor over her eyes flickered, then shattered into fragments of light. Her body trembled once, then slowly dissolved from the center of her torso outward, turning into drifting particles.
Silence.
The train remained still. The lights buzzed faintly above me.
Gáe Bolg dispersed into prana. My knees almost gave out. That attack consumed too much mana.
Before I could think further, a notification appeared.
[You have defeated Jun-Ninja]
[Classification: Tier 5 – Level 5]
[Threat Rank: Village-Class]
[1st Trial Cleared]
[EXP Gained: 1,800]
[Level Up]
[Level 5 → Level 20]
A blue light wrapped around my body briefly. Fatigue eased, and my circuits felt more stable. Level 20 already. That's fast. My body felt noticeably stronger, and even the tiredness from the heavy mana consumption was gone.
Then my attention returned to a single detail. Tier 5.
"What is Tier?" I muttered. I didn't really know. This was the first time I encountered the concept.
A new window opened.
[Tier System Explanation]
[Tier measures qualitative threat level based on destructive capability and combat authority.]
[Tier 10 – Extremely weak entities (minor slimes)]
[Tier 9 – Weak monsters (goblins)]
[Tier 7–5 – Standard combat-capable creatures]
[Tier 6 – Town-Class threat]
[Tier 5 – Village-Class to Low City-Class threat]
[Tier 3 – City-Class threat]
[Tier 1 – World-Level threat]
[Tier 0 – Calamity-Class / Multiverse / Higher-Dimensional threat]
So Tier is about overall danger, and Level is just growth.
Even something low-level can be high Tier if its structure or capabilities are abnormal. Like that Jun-Ninja: Level 5, Tier 5, Village-Class. If it appeared in a normal rural area without a trained magus or hunter, it could have wiped everything out.
I checked my status.
[Emiya Shirou]
[Level: 20]
[EXP: 20 / 200]
[HP: 3,364 / 3,364]
[MP: 126/126]
[STA: 3,249/3,249]
Tier: 10
Strength:12+3(15)(-F) → 57(F)
Agility: 11+3(15)(-F) → 56(F)
Endurance: 13+3(15)(-F) → 58(F)
Magic: 10+4(15)(-F) → 63(+F)
Luck: 3(-F)→ 18(-F)
SP: 400
Condition: Healthy
Skills leveled up slightly:
Cooking Lv40 → Lv45 – Precision in taste, aroma, and presentation improved.
Archer (EMIYA) Lv8 → Lv12 – Weapon projection, summoning, and mana management became smoother.
Dual Blades Technique Lv9 → Lv12 – Transitioning between attacks is now faster and more fluid.
Trigger-On Lv3 → Lv5 – Mana consumption reduced, output stability increased.
Sword Barrel Lv4 → Lv6 – Projected swords maintain durability and speed for longer bursts.
Level 20 already.