That afternoon, I headed to the Research Institute alone.
It was time for my routine progress check. Although I had already received her written reports, I found it far more effective to see the results with my own eyes.
Just past the entrance, the Institute Director stood waiting for me, her lab coat draped over her shoulders. She greeted me with a profound bow.
"My Demon King, welcome! I have been waiting for you with all my heart!"
"Good work. I apologize for intruding when you're busy."
At my words, the Director shook her head and waved her hands with frantic exaggeration.
"No, no, not at all! I am forever in your debt, my Demon King, so please let me be of service! Besides, since you granted me this body, I’m perfectly fine working without rest or sleep!"
She puffed out her chest with pride. However, both of her legs were translucent from the knees down. Her physical form was hazy, and her skin was a shade of blue-white that went far beyond being merely unhealthy.
As her appearance suggested, she had abandoned her humanity. She had transformed into a Phantom—a high-ranking spirit-type undead. Depending on the individual, a Phantom could command legions of lesser spirits to claim its own territory. Even on their own, they possessed formidable power.
To be honest, this hadn't been the intended result. My original plan was to turn her into a Ghost—a more common type of spirit that could retain its ego. While not particularly powerful, a Ghost’s strength was irrelevant for a researcher. They were easy to create, reliable, and freed the soul from the needs of flesh like fatigue or sleep. Since they could partially materialize, it wouldn't have hindered her work at all. It was the ideal race for her.
I had performed the Ghostification ritual exactly as planned, and the spell had succeeded without a hitch. Yet, for some reason, she had manifested as a Phantom instead.
It wasn’t a mistake on my part. I reviewed the process multiple times afterward, but the ritual hadn't failed. After considering various possibilities, I formulated a single hypothesis: the cause lay in the Director’s own psyche.
Her singular, overwhelming obsession with her research had forcibly elevated her existence as an undead. Strong thoughts act powerfully upon magic, and this effect is only magnified when the soul discards its physical vessel. I couldn't think of any other explanation. I had always been struck by her intense temperament as a researcher, but I never expected it to be quite this extreme.
In any case, becoming a Phantom wasn't a bad thing. It was a superior race, after all, and possessed no disadvantages compared to a Ghost.
"Do you find your new form inconvenient?" I asked.
"Not in the least! I’ve lost the ability to eat or sleep, but I always found those things to be a nuisance anyway. Since taking this form, my work efficiency has skyrocketed! Plus, I no longer get injured during lab accidents, so it’s all been wonderful!"
Floating at a low altitude, the Director paced around the room as she spoke in her usual rapid-fire manner. As she moved, a stray beam of sunlight near the entrance grazed her. She let out a shriek and rolled away with theatrical flair, disappearing into the shadows of the institute.
The other staff members watched her antics with looks of weary annoyance.
Being a spirit-type undead, she clearly retained an aversion to sunlight. That said, a Phantom won't vanish instantly upon exposure. Since it wasn't life-threatening, I didn't see much cause for concern. Besides, she had hated the sun even when she was human, constantly lamenting that she wanted to stay cooped up indoors forever. In that sense, her current state wasn't much of a change.
Feeling a bit exasperated, I followed her deeper into the building. The Director quickly recovered from the sunlight and moved to lead the way.
"By the way," she asked, "have you come to see the 'usual' today?"
I knew exactly what she meant. Since there was no reason to hide it, I nodded.
"Yes. Any issues?"
"None at all! We’re monitoring it strictly. If even the slightest anomaly occurs, the alarm system will trigger instantly."
The Director wore a fearless, confident smile. Affecting a sophisticated air, she adjusted her glasses with a finger. She no longer had a physiological need for them, but she continued to wear both the glasses and her lab coat—perhaps out of some personal habit.
We descended to the fifth basement floor. This area had been built within the last six months as the facility steadily expanded. Between the new wings and the above-ground extensions, it had become the preeminent research center in the Royal Capital. At this rate, it might eventually grow larger than the Royal Castle itself.
The Director cleared several layers of locks and led me into the deepest chamber. When the final door opened, I saw a glass container fixed in the center of the small room.
The Director stepped aside at the entrance. "Please, see for yourself."
I nodded and stepped inside, focusing my gaze on the container. Sealed within by multiple barriers, a substance resembling black water floated in the air. It writhed irregularly, a mass of dark, fluctuating energy.
This was the soul of the former member of the Four Heavenly Kings, Barulk. I had killed him when he attempted a secret resurrection, and when his shattered soul began to repair itself yet again, I had gathered the fragments and sealed them here. It had been a considerable amount of effort, but he was far too dangerous to leave alone.
Currently, we were systematically destroying the soul as it tried to mend, preventing his restoration while simultaneously eroding his ego. Barulk had been reduced to little more than a mass of lingering thoughts. He was likely no longer capable of conscious thought.
Even so, Barulk's tenacity was nothing short of marvelous. He had attempted to overcome death twice through sheer force of will. Had I not intervened, he likely would have achieved a full resurrection within a few years. He was an undeniable superhuman, driven solely by his desire for revenge against me and the restoration of the former Demon King’s Army. I couldn't help but feel a chill at the thought of such iron resolve.
This room served as a permanent observation post. While we monitored the soul, we were also analyzing the mechanism behind its self-repair. My goal was to pioneer a new system of resurrection technology. Bringing someone back from a state where even the soul had been destroyed would be a monumental achievement. If we could replicate it, the applications would be endless. It was exactly the kind of breakthrough needed to revitalize our stagnant research.
Once I finished my observation, I stepped back out into the hall. The Director locked the door behind us and looked up at me.
"Is that all for today?"
"Yes. The check is complete. It's sufficient."
As we walked back toward the upper floors, the Director began to chatter away.
"Regarding the soul repair art, systemizing it is proving to be quite a challenge... There are issues with personal aptitude, and we’re still lacking in our analysis. It feels less like a general spell and more like a unique ability inherent to that specific soul."
"It sounds like you're struggling. And yet, you seem happy about it."
"Oh, absolutely! It makes the research so much more rewarding! I’m more fired up than ever. If I were still human, I would have died from overwork ages ago!"
She gave me a bright smile and a thumbs-up. In her case, it wasn't a joke; she truly had been on the verge of death from exhaustion before her transformation. Seeing her so immersed in her work, I felt glad once again that I had turned her into an undead.
She beamed for a moment longer before a look of realization crossed her face, and her expression turned awkward. She hurriedly bowed her head to me.
"Ah, but from your perspective, my Demon King, a delay in analysis is a failure! My sincerest apologies!"
"No, it doesn't matter. I understand how difficult the task is. Proceed at your own pace without rushing. I'll leave the timing to your discretion."
When I said that, the Director froze. A moment later, her entire body began to tremble.
"A-Ah... ahhh... ah..."
She began to leak broken, incoherent murmurs. I was starting to wonder if something had gone wrong with her phantom form when she suddenly prostrated herself on the floor before me. She pressed her forehead down so hard that it actually phased through the floorboards.
"Thank you so much!" she wailed. "I am truly, deeply moved! I will give it my heart and soul—I'll work until I die again! Yes, I will!"
"...I see."
Taken aback by the sheer intensity of her gratitude, I couldn't find a single word to say in response.