Walking down the sprawling white corridors of the lab, I led along one unpredictable girl who'd earned herself the nickname "The Demon" among the people. My goal was to study her demonic magic.
"Mages sometimes experience Take Over differently. How do you interpret the process?" I asked Mirajane, who kept craning her neck every time we passed a room with some piece of equipment or another.
"Huh? I just do it however it comes out." She shrugged and went right back to satisfying her curiosity.
"So you don't understand what's happening to your body on a cellular level?"
"The hell? I just punch a demon and absorb its power!"
"...Remarkable."
"You don't ask for help very often," Mirajane said, finally done rubbernecking. "Can I expect something out of this after we're done?"
"Before you hit S-rank, I took you on a couple of S-rank missions. Consider this payback."
My cold tone earned me a pout.
"You're so petty, Elian!"
"Absolutely." A smile crept onto my face, turning playful when I caught her eye. "And you actually can be kind. You can drop the attitude, you know."
That second line, which I practically sang, made Mira flush crimson on the spot.
"We had a deal that you wouldn't bring that up!"
"Did we?"
"You've 'forgotten' five times now! Knock it off!"
"We didn't have a deal. But you really, really wanted one..."
That little secret of hers, that her whole The Demon act wasn't some evolution of her character but just a mask, I'd figured out when she was around thirteen. It made sense, thinking back to the day we met, when she'd been crying and yet genuinely happy after her younger siblings promised they wouldn't leave her over her demonic arm. That meant she didn't always act like an ass, and was perfectly capable of being kind. When I'd first said that out loud, the eldest Strauss had immediately spiraled into a panic about Erza, her chief rival, somehow finding out this terrible secret. With that, Mirajane had fully given herself away, and she still hadn't managed to wriggle out of it.
So, having demonstrated once again that I could dish it out just as well as I could threaten to beat her with a piece of rebar, we arrived at our destination.
We stepped into a large hall where an enormous contraption sat at the center. It consisted of a two-by-two-by-two-meter metal chamber, plus a serpentine network of metal structures stretching across the entire room, bristling with glowing holographic surfaces, screens and keyboards everywhere.
"The demon is inside the energy analysis chamber. The specimen's in stasis, but we can kill it if needed," I said, running through a quick refresher briefing as we approached. "Main thing, don't shift into demon form..."
"Yeah, yeah, I'm not stupid! The equipment's sensitive and I could break everything by accident. I remember, you told me."
The girl walked right up to it with confidence, then looked over two more devices that a couple of lab techs had wheeled over on casters. Those devices were actually much larger in principle, though these little boxes, hooked up via thick cables, were just convenient mobile hubs for plugging in various sensors.
"Hand." I held out my palm, and Mira's wrist landed in it shortly after. A needle was inserted into her vein. "This is for monitoring internal transformations. One device is focused on biological analysis, the other on energetic analysis."
The girl glanced over her needle-studded arms, two in each, along with a handful of adhesive sensor pads with wires already stuck to her body. Then she looked up at me.
"You know, I'm not all that interested in this... What I'm more curious about is how you'd look in a doctor's coat. Want me to give my verdict?"
"Erza's more into the dress-up thing," I deflected Mira without missing a beat. Year after year, her little "advances" never stopped. She'd apparently decided to treat it like some kind of competitive sport she was determined to excel at. "In a nurse's uniform, she's something else."
"Don't bring up other girls when you're talking to me."
"Sir, all readings are nominal," said one of the lab technicians, standing a little ways off behind a large hologram bristling with graphs. "Equipment is ready to record."
"Good, start it up," I ordered, then turned back to a scowling Mirajane. She was scowling because her protests had just been completely ignored. "Don't make that face. You look like a Pallas cat. We're waiting on your end of this."
Earning a "hmph" in response, I watched as the girl stepped into the analysis chamber and placed her hand on the head of a brownish-green, horned creature. It was a demon captured in the jungle, not particularly powerful, about a meter and a half tall. By its own race's standards it was genuinely pathetic, but it suited the experiment just fine.
My own hand, meanwhile, rested on a small pedestal nearby. I ran magic through my arm, and a hum began to build in the room as a cascade of images, Mirajane's body and magic, started reflecting through my mind. Essentially, I'd linked my consciousness to all those sensors reading the test subjects, acting as both an amplifier-sensor and one of the conduits through which the data flowed.
The girl attempted to absorb the demon while it was unconscious. She clicked her tongue in disappointment when it didn't work. I, meanwhile, felt every fluctuation and image of what was happening, not just inside the chamber but inside both subjects' bodies. The demon was hooked up to the equipment too, naturally. And I tracked everything: from the moment Mira's magic latched onto the demon's energetic essence inside its body, all the way to the hormonal spike of irritation she released when the attempt failed.
Then the ether briefly dissolved into static across my analyzers as the girl channeled a small amount of magic to reinforce her body.
A sickening crack rang out, and under Mira's reinforced hand, the demon's neck snapped.
The people in the lab flinched. I methodically continued watching the most interesting part.
The demonic particles inside Mirajane's body activated again. Particles, not cells, since their nature was more energetic than biological. After that, transforming her entire body into a conduit, the particles pulled the demon's demonic energy toward themselves under the influence of her magic. With its body broken, the demon couldn't put up much of a fight, and before long its energetic body, soul and all from what I could see, ended up in some sort of subspace near Mirajane's core. She tensed for just a moment, then effortlessly crushed every last shred of the demon's will, bringing it completely under her control. The demon's previous shell, its physical body, crumbled to ash.
"So?" she asked, stepping out and clearly showing off.
"Not bad. But your body reinforcement hammered the sensors. You could've just asked us to push the demon to the brink of death ourselves."
"Hey! I was trying, you know! And look, I didn't even break anything!"
On that note, to the accompaniment of Mirajane's grumbling, I gave the order to have all the recordings prepared for review, and the two of us headed outside. We still had one more piece of business, but it required getting away from Magnolia.
"Last thing I want to see today. Release your power," I suggested once we were out in a deserted stretch of mountain terrain.
"With pleasure, watch and be amazed!"
Something seemed to click inside Mirajane, or more precisely, her demonic particles activated once again. But this time, an enormous surge of magical power flooded into her from within. I observed it purely through my own magical sensitivity, but having seen the process up close earlier, I already understood what was happening.
With an erupting roar, pressure came crashing down on me as a gust of wind blasted outward from Mirajane, sweeping the dust from around her. A dark violet aura rose from the girl as the very stones beneath her feet began to fracture. Her body shifted too: a long tail appeared behind her, plated with large segmented scales; her hands transformed into massive claws covered in the same scales, and fin-like growths sprouted from her elbows. Dark veins traced across Mira's skin, her ears tapered to points, and her hair lifted into the air.
With one arm raised to shield my face, my focus stayed locked on analyzing the transformation process. But before long, the voice of "The Demon" pulled me out of my thoughts.
"Well?" The girl was showing off again, striking poses and continuing to radiate magical power.
During the transformation itself she'd released a particularly intense surge of energy; now, under its pressure, I could at least stand still without effort.
"Impressive." At my sparse praise she practically lit up. "With that, thanks for your help."
Having gotten what I needed, my humble self was fully prepared to leave Mirajane's company. I even managed a few steps before her expression shifted quickly to something hurt. I stopped as a pair of very human arms wrapped around my torso from behind.
"Why do you still ignore me?"
I sighed at the plaintive question.
"Same reasons as before."
"But... I've grown up!" Something fairly substantial was pressed into my lower back for emphasis.
"Not grown-up enough. Mirajane, your attention is flattering, I'll give you that. But you act like a pushy, rebellious teenager half the time, and it gets old. On top of that, I'm focused on my research right now, on getting stronger. I'd suggest you focus on the same."
In that moment, my behavior was peak isekai protagonist, walking away from a beautiful girl without a second thought.
"But I'm already strong! And you're not weak either. We're both S-rank."
"A lot of 'buts'." Another sigh escaped me, and I turned to face her, pressing my forehead against hers. The position looked pretty romantic, objectively speaking. "Do you actually want to be with me that badly?"
"You... You were the first person to treat me like a human being, outside of my own family. Even with that terrifying demonic arm." She swallowed and looked away. It was clear the words had cost her something.
"And I don't look like an eighty-year-old dwarf?" A smile appeared on my face, which made Mira wince.
We stepped apart.
"Hey! That could've been our first kiss! And you ruined it!" The accusations came flying again, but Mirajane settled down soon enough. Her voice found its calm again, along with something almost shy. "Besides, you were the one who helped me with that book, not that creepy old geezer. What am I even supposed to feel, other than gratitude and everything else? And honestly, have you seen the other guys?! They've all got rocks for brains! Natsu and Gray only want to punch each other's faces in. I'd bet money they don't even know girls have a vagina and not a dick down there! And the rest aren't much smarter."
"That's one hell of a love confession," I commented.
"Like you didn't already know how I felt." She snorted and raised her chin, arms folded.
"Let's make a deal. In some ways, you're not that different from those guys yourself. You're pushy, and you genuinely don't understand your own worth yet." She choked on air and shot me an indignant look. But I kept going. "I've been telling you this for a while now. You don't get it. Fine, better to show you."
And before Mirajane could get a word in, my eye flared red, and her body went rigid. Moments later she collapsed into my arms, paralyzed.
Only a minute later, once I dissolved the spell, Mira woke in my arms, her head resting on my shoulder.
"That was high-level sleep magic," I explained to her bewildered look. "You have no real defense against a lot of dark arts. Your magical power is overwhelming, but it can be completely useless in the right moment. That's just the kind of treacherous world this is. It's not just me, you have plenty to work on yourself. So that when you run into a mage from a dark guild, he can't just freeze you in place and do something very, very bad to you..."
During my explanation, the girl's face cycled through expressions like a storm, a wild, shifting cocktail of emotions. Fear and wounded pride from being made to feel helpless. The painful, gut-level recognition of the responsibility she carried for her own life and her siblings', the knowledge that a gap in her skills could cost them everything. And then a grim resolve settling over her face at the end.
"Not every mage can pull off that kind of magic. But there are plenty who can. Become a genuinely powerful mage, and then we'll go on a date."
I set Mirajane back on her feet and turned, taking a step. Her hand caught me.
"I promise I will. And when I do, you won't be walking away from me..."
"Ha! Sounds like a threat. I kind of like it, though, so no hard feelings."
"Yeah." Her confidence snapping back into place, she crossed her arms under her chest. Full-on proud now. "And in the meantime, while I'm training, go to hell, Elian! And don't you dare find a girl before I can counter every last dirty trick you've got!"
She turned and, "proudly" in quotes, just ran.
"Tease!" Mirajane called back over her shoulder, and then her silhouette disappeared behind the hills.
All I could do was blink.
And so that awkward milestone in Mira's journey came to a close, and I went about my business.
Honestly, I genuinely did appreciate the attention of a girl who was actually someone worth appreciating. She wasn't just a rebellious teenager. Her personality was full of mature qualities: she understood responsibility, the weight of being an older sister. Back in that village, the Strauss kids had lived without parents for a long time, and it was Mirajane who'd stepped into that role. Her feelings for me were genuine too, and not something she'd just stumbled into. But those moments. Everything got wrecked by those moments.
The way she treated everyone around her like they were beneath her. "I will become the fear, before fear becomes me again," or however she'd rationalized it to herself walking out of that godforsaken village where the Strausses had lived and been despised. In short: Mirajane had welded the The Demon mask to her face so she'd be the one doing the frightening instead of the one being frightened. That doesn't sound entirely logical written out like that, but there's a ring of truth to it. And that's exactly what I didn't like, the mask specifically. Because it smothered the rest of her, all the warmth, all the genuine care, and left something incomplete. Add to that the teenage emotional whiplash: one second she swore she'd win me over, the next she was telling me to go to hell, and thirty seconds later she was demanding I not look at another girl. The emotional roller coaster was doing a number on my sanity. Which is exactly why I'd rather keep things calm in my life. In Mira's case, that would sort itself out with time and plain old growing up. Or it could resolve faster, if I kept pointing out that she was burying her better qualities under a wall of tsundere aggression. But Makarov has a point: we grow stronger by making our own mistakes. Right now, her emotions could serve as fuel for the goal I gave her, getting stronger as a mage. Two birds, one stone.
And so my inner monologue about who everyone was and what kind of person they actually were wound down, somewhere out there in those same mountains. But I had things to do, and soon enough I was headed back to the lab at a much quicker pace.
Mirajane's demonic factor needed further study, and I spent the following week doing exactly that.
Then one day at the guild, spotting The Demon planted in the library, I walked over to Natsu.
"Hey, kid—"
"You looking for a fight, Elian?! We're the same age!"
"Couldn't care less. You want a free meal on my tab?"
At that question, his face went from murderous to delighted in about half a second.
"That's what you lead with next time! Who do I gotta burn?" He flashed a dumb, dopey grin.
"Nobody needs burning right now. I just need you to show up at my lab and use some magic. Oh, and eat some fire."
"Hell yeah! And they're feeding me fire on top of it!"
"Yo, Elian!" A blue cat dropped in on white wings, Happy, who followed Natsu everywhere these days. "Can I do some magic too? You give me fish."
"Hmm..." I thought it over. This little cat had picked up on the deal pretty fast. "Not exactly the data I need right now, but yeah, sure, works for me."
Before long we were at the lab, where my staff started wiring up the sentient animal to the equipment.
"How come he goes first?" Natsu asked, looking genuinely confused.
"Because I trust Happy more. What if you pull something? At least this way we get through the full round of tests."
"You trust him more?! How?! He's a cat!"
"You got a problem with cats?" Happy said, his face doing something deeply unsettling.
"Whoa!" Natsu somehow ended up behind my shoulders without anyone seeing him move. "Hey, don't make that face! That's Erza's face! That's scary!"
I got the circus under control, tied the pink-haired menace to a chair, and ran through all the measurements with the cat quickly enough. He was genuinely a sentient being with actual magic, not a shapeshifting mage playing at being a cat, not a shared hallucination, but the real deal. Getting deeper into the biology of this particular creature would require a much more thorough dive into the data, and that wasn't happening anytime soon.
Then it was the pink-haired blockhead's turn to climb into the chamber. Happy's session had gone smoothly enough, he simply wasn't strong enough to break anything, but with Natsu the problems started immediately.
"Turn it down, idiot! The sensors are starting to melt!" I shouted at the guy, who I'd asked to produce a weak flame.
"This is normal fire! This is how I always burn stuff!" he protested.
"And I told you to make it weaker than usual!"
"Natsu is dumb. Can't follow simple instructions," Happy said cheerfully, pouring oil on the fire.
"What did you just say?!" Natsu caught fire all on his own from pure indignation.
An alarm screamed from somewhere in the hall, signaling critical temperatures.
"Both of you, cool it!" I snapped. Natsu guttered out immediately, and Happy slapped both paws over his mouth.
"Ooooh... now he really is like Erza," the cat murmured.
"Erza drills you more often, that's why you're more scared of her. But I can beat you up just fine. Ask Natsu."
I nodded toward his buddy on Happy's behalf, and the Dragon Slayer dutifully confirmed, yes, he had in fact been smacked by me more than once.
"Everyone in this guild is terrifying... Erza's terrifying... Mira's terrifying... Elian's terrifying..."
"Alright, I've had it." Done tolerating the circus, I taped the cat's mouth shut, tied him to a chair, and turned back to Natsu. "You are going to listen carefully and do exactly what I say. If you don't, I won't just cut off the food, I'll beat you black and blue. Understood?"
I made the threat land by loosing my Bloodlust. Since I had no actual desire to kill the kid, the killing intent came out a bit muted. But it was more than enough for him.
"A-ah... Natsu listens to great boss Elian! Natsu follows all commands!"
"Wonderful."
The remaining experiments, including running fire through a lacrima for the Dragon Slayer and watching him devour the element, went reasonably well. No casualties as far as anyone could tell, and all the data I needed was in hand.
"Thanks for your work," I said to the two of them, and they both got a little awkward about it.
"Don't mention it. We're guildmates." Natsu waved it off.
"So. When do I get my fish?" Happy asked in the same flat tone, as if the guildmate speech hadn't just happened and he wasn't being completely mercenary about it.
"Yeah, where's the food?" the Dragon Slayer was quick to add.
"Julian, take the guests to whatever diner they want," I said to one of the less critical lab assistants. "I'll cover it out of pocket."
With the two of them paid off and out the door, I exhaled and turned my attention to the sensor data. But the more closely I looked, the more clearly something was off.
In a rush to check, I asked another lab tech to open the fire feed at a hundred units, then put my own hand on the measurement pedestal. A few seconds later, a string of sentences came out of me that were not entirely fit for print.
"Of course! He burned out the sensors after all! I was wondering why the sensitivity dropped."
Between the recalculations and the choice words, I started disassembling the equipment for inspection to get a damage estimate, and it came out to roughly ten million jewels. Not a significant amount at my current point in life, but what made it infuriating was that certain experiments would have to go on hold while pieces of lab equipment got taken apart and shipped by train to various specialists for repairs.
Eventually I calmed down, and even decided not to take revenge on one particular fire-breathing little punk.
All things considered, getting access to study the ancient, lost magic of Dragon Slayers for the cost of lunch was genuinely a gift. Even shelling out ten million for it was cheap.
Beyond Natsu, there were other Dragon Slayers around, of course. God Serena, from what I'd heard, was one as well. The only thing was, I had a feeling the "Wizard Saint's Wizard Saint" would charge somewhere in the nine-to-ten-figure range to let himself be studied. Or, more likely, he'd just tell me to get lost for even suggesting it. After all, why would he, of all people, let someone learn his weaknesses?
As for the other Dragon Slayer I did have access to: Laxus, a month later, once the lab was back to full capacity, agreed to undergo a checkup with yours truly. To be fair, the guy was smarter about it. He charged me as though it were a straightforward S-rank mission, and on top of that demanded my word that I wouldn't use his genetic data to engineer a custom illness that would hit him with maximum-strength diarrhea at random intervals. How he found out I was capable of something like that, I had absolutely no idea, but I gave him the promise.
The full results from studying the Dragon Slayers and one demon-devourer didn't land in my hands until a few months after that, following a good long stretch of chewing through the data to actually understand how any of it worked. And if I were to put it in plain English rather than the endless scientific notes I'd accumulated by the end of the research, the picture looked something like this:
"The Demon" actually had very little to do with demons directly. She had a demonic factor, demonic particles that had taken root in her and become part of her energetic makeup. Where they came from in a girl like her was unclear, but my working theory was that somewhere in her ancestry there was someone who'd wielded the lost magic of Demon Slayers. I'd never seen an actual Demon Slayer in my life, let alone studied one, but that's what working theories are for. It just sounded logical. The truth remained unknown.
So those demonic particles in Mira were nothing more than a conduit. She captured the energetic bodies of demons and stored them inside herself. From those demonic energetic bodies she could draw dark power, meaning she herself was not a demon and produced no demonic energy of her own. She just had batteries packed inside her, generators she could tap into one at a time.
That said, she did have magic of her own, and she could use it perfectly well without relying on borrowed power.
The Dragon Slayers, to my genuine surprise, were far more distinct from each other than I'd expected. Laxus had a Dragon Lacrima built into him, a standalone organ and reservoir of his power. Natsu had no such thing, yet he still differed physiologically from a human more than just a little, shifting toward predatory traits that I now cataloged as draconic. And the cause of those dramatic changes was a strange formation inside Natsu's magical container itself. So while Laxus had undergone a partial mutation toward dragon-hood and stopped there, Natsu's process should have kept going, were it not for certain antibody-like cells discovered in him that were actively blocking it.
Where those cells had come from, I had no idea. They were substantially different from anything a human body could produce. What was clear was that Natsu was some kind of mutant, someone who had been in the process of transforming into a dragon and had that transformation stopped in its tracks.
All of this was interesting. Fascinating, even. My nose had clearly found its way into someone else's secrets. But the most staggering discovery came with something else.
While studying the Dragon Slayers' genetics, I'd had an itch in the back of my mind, a nagging sense that I'd seen something like this before. And when I checked, sure enough, I found more than a few of the same traits in myself. Not the mutation in the source, not a Dragon Lacrima, but the profile looked like at least one of my parents had been a dragon.
When I then checked Erza's blood and magic, my excitement spiked further. Yes, she had plenty of the same markers, but the draconic genes were even more pronounced in her than in me, which accounted for her naturally superior physical strength and reflexes.
But what really set me off was a different fact, one that, in retrospect, followed logically from everything else:
"What was the local Creator smoking? How does something like this even get designed?" I asked the ceiling, sitting at the monitor in my office. "We look alike. Our magical affinities are alike. And we were brought in the same basket... How could we possibly not be twins?"