The Royal Military Academy's Impostor Owns a Dungeon [BL]

After more than 200 space hours trying to build a biomecha for one anxious little system, they were finally trying it on today.

Finally!

The nearly completed biomecha loomed in the center of the hangar, its frame a patchwork of gleaming alloys and skeletal connectors.

It was huge, just like the other mechas but Luca only realized just how imposing it would be like once it was assembled like this.

And although unfinished, the disbelieving mecha maker could already imagine what it could look like with that expensive plating that hadn’t even been polished.

Yet, as it is, Luca was already pretty happy, and if not for D-29’s insistence on aesthetics, the penny pincher would’ve been fine with this look as long as it worked.

Provided it works.

Which was exactly the point of their current gathering.

Despite how far they’d come, one simple truth still hung in the air:

They might fail.

Especially after D-29’s very insightful yet seriously gleeful exclamations of how ”There’s only a 37% chance of catastrophic failure, Host!”

And when asked where this obviously daunting number came from, the little system proudly prompted, ”Host, about that... I may have factored in your past success rates with first attempts.”

”But don’t worry, I applied a slight bias to account for emotional resilience!” It added cheerfully or as cheerful as a handful of animated cheers could go.

However, even the system was worried as this was something the Host had worked hard on.

And it was all for D-29.

All for the system to test if it was really possible to connect as the AI of the biomecha like it did with Sid.

It was just that they couldn’t run the Synapse reactor until this test was done and would have to do it with Luca actually supplying energy as a pilot.

And this was something that Xavier almost dissuaded him from doing.

It was one thing to build it, but another thing to test it for the first time.

This was akin to sitting inside a possible bomb while lighting an accidental fuse.

But Xavier stopped himself.

Since he trusted his little chipmunk, then the Prince should trust him with decisions like this.

However, that wouldn’t stop him from standing close to the trove in case he needed to purchase a revive pill.

And well, there was also checking and re-checking for any leaks with his visual resonance.

So, when Luca said, ”Okay. Last check. Are all the connectors in place?”

Xavier was able to respond with, ”Verified. No energy leaks detected. Stabilizers are aligned,” after checking for the seventh time.

”And if it doesn’t work?” Ollie asked in a murmur, actually trembling in his boots.

”...”

No one really wanted to answer that because it likely would be distressing in every way.

So, instead of acknowledging the elephant in the room, they just fixed their gazes on the hangar’s main console, quietly ensuring every single readout was accounted for.

”If anything looks unstable,” Xavier said in a low voice, ”you disengage. Immediately.”

Luca nodded.

Because Xavier looked at tad bit scary, and he also had no death wish.

But as he moved toward the cockpit, he couldn’t shake the twinge of worry.

What if he made a mistake?

Or forgot something along the way?

Or, worse, didn’t know about something crucial?

The biomecha wasn’t just a project. It was the culmination of weeks of sleepless effort, countless recalculations, and stubborn, endless trial and error.

And it was also going to be D-29.

The cockpit hissed open with a hydraulic whirr, exposing the pilot’s seat and the strange, nerve-like cables that lined the interior. It was both clinical and oddly alive — a reflection of the mecha’s organic integration.

”Ready when you are,” Luca murmured, though it was mostly to himself.

He settled into the seat, the grip of the restraints activating automatically. Despite the heavy thrum of the hangar around him, the inside of the cockpit felt eerily still.

The moment he touched the interface, a pulse of warmth greeted him. The mecha was waiting.

”D-29.”

”Yes, Host?” The little system’s prompts had shifted, still chipper but tinged with something else.

”Nervous?”

”Ideally, no, Host. But considering the circumstances, I should be. When faced with major events like this, they always say that the heart ba-dumps.”

That was very much like D-29, and Luca smiled faintly.

”Beginning connection sequence.”

Outside the cockpit, Xavier and Ollie braced. The hangar’s lights dimmed slightly as the system drew power.

The bio mecha’s core flickered, not with the vibrant, unnatural blue of conventional reactors but with a golden hue—warm and steady.

D-29’s presence expanded.

”I’m here, Host,” the little system whispered, though this time, the voice came from everywhere at once. A hum resonated through the biomecha’s frame. The cables tightened, and the joints gave a faint whirr.

And then—

Silence.

The reactor’s glow remained steady, but nothing else happened. The biomecha’s limbs remained still, unnervingly so.

Seconds stretched.

Luca’s fingers hovered nervously over the controls. ”Uh, D-29?”

What just happened?

Wasn’t it alright earlier?

No response.

Xavier’s jaw tightened. ”Did it—”

”—Fail?” Ollie finished, voice tight.

The golden glow didn’t flicker. The energy readings still held stable, but the complete lack of movement made every second feel heavier.

Luca swallowed. ”D-29, are you—”

The little mechanic was extremely anxious.

It was one thing to fail in creating a biomecha that could house D-29, but it was a totally different thing to lose his friend from failing at this.

”Oh! Oh, sorry, Host!” D-29’s voice finally burst through, chipper as ever.

”I was just... um... checking something!”

”You were what???”

”Well...” There was a tiny, awkward pause. ”I didn’t know which leg goes first.”

Luca blinked. ”What?”

”You know! When you walk!” The system sounded strangely embarrassed. ”I couldn’t remember if it was the left or the right leg! And Sid wasn’t answering me right away, so I had to wait until he confirmed it!”

”...”

”Apologies, Host. He’s the best at limb stuff! I mean, he almost had a lot of them!” D-29 chirped as if that were the most logical answer in the universe.

There was a beat of silence.

Xavier pinched the bridge of his nose. ”So, just to clarify. You didn’t crash. You didn’t overload. You... forgot how to walk.”

”Technically, I never knew how in the first place!” D-29 said brightly.

Luca, despite the sheer absurdity of the situation, laughed — a breathless, relieved sound.

And just like that, the knot that had taken root in his chest was just untangled.

”Alright, alright. Left leg first. Got it. Ready when you are.”

There was a hum of determination from the system.

’Left leg first!’

Finally, the massive frame of the biomecha shifted. One enormous metal leg creaked forward in a deliberately careful motion. The joints held—there were no sudden sparks, no catastrophic collapse.

Another step followed. Awkward but functional.

”I’m doing it!” D-29 cheered. ”Host! I’m walking!”

Luca’s smile grew, the weight of anticipation finally lifting. ”Yeah,” he said softly. ”It’s working.”

The biomecha stood tall, its limbs now moving with a semblance of stability.

Awkward, yes.

But undeniably functional. D-29 had proudly managed a few shaky steps, and Luca was grinning like a fool in the cockpit.

But the real test had yet to come.

”Okay,” Luca exhaled, steeling himself. ”That was... promising.”

”Very promising, Host!” D-29 added cheerfully. ”Left leg, right leg — I’m practically a professional walker now!”

”Congratulations,” Sid interjected.

”Now, try not to explode.”

Because the next step wasn’t just walking.

It was the Synapse Reactor.