The World’s Finest Assassin Gets Reincarnated in Another World as an Aristocrat - Volume 1 - Chapter 7

Chapter 7 | The Assassin Utilizes Knowledge from His Previous World 

It had been nine days since Dia’s arrival. The mage was mature for her age, but I’d noticed she was prone to bouts of loneliness and acting like a spoiled child.

The day before, she’d told me it was too lonely for me to sleep by myself, despite my age. Then she immediately climbed into my bed and used me as a body pillow.

Because of how young we were, there was nothing sexual about it, but for some reason, it still set my heart racing. When Dia hugged me, I became strangely aware of her sweet fragrance, her softness, and her warmth.

“Lugh, you’d better make sure to listen to your big sister today.”

“… When did I become your little brother?”

“Ah, Lord Cian hasn’t told you about that thing. Well, regardless, this is an order from your mentor: You’re now my little brother!”

That thing? I wondered. Is Dia saying she’s a child of my father’s from another woman? No, that’s impossible. 

Since Dia was my mentor, I’d gathered as much information on her as I could. Dia’s last name was Viekone. There was no noble family in Alvan with that name. There was, however, a count in a neighboring country with that name.

My mother was purported to have been a commoner, but she had mana, and her elegant demeanor and etiquette were too refined to have been adopted later in life. Everything about her would’ve made you think she was born into a wealthy family.

Dia reminded me a lot of her. They both had the same distinct silver hair, a similar physical appearance, similar habits, and they both spoke with a slight accent to their speech that you otherwise didn’t hear anywhere in Alvan.

I’d been wondering if maybe Mother was born into House Viekone and had disguised her social status before marrying Father. Were that true, there was a good chance Dia was my cousin.

“Got it. I’ll follow my mentor’s orders,” I responded.

“Hmm-hmm, I’m glad we have an understanding. Man, Tuatha Dé food is delicious!” Dia said through a mouthful of gratin.

Yesterday I’d brought home another rabbit and served cream stew again. Today I took the leftovers and used them to prepare gratin. I added pasta and spice to the stew, then I further altered the taste by sprinkling in some dried tomatoes. After that, I added ample amounts of cheese and baked it in the oven. The mixture quickly became a delicious gratin.

“Sorry I couldn’t make anything fancier,” I apologized.

“I’m sick of that kind of stuff. Gratin has a really nice taste. I love it,” Dia replied.

“I’m glad.”

“… How are you able to do all this at just seven years old? You seem to have an extensive knowledge of just about everything, and you’re smarter than me despite being younger. Everyone called me a genius, but you’re on another level.”

“It’s all thanks to my parents’ education. Oh yeah, I need to go grab something for dinner later. I know you’re going to like it.”

It was almost the season when the pheasants fattened up for the winter, which made them really tasty. Once today’s magic research had ended, I’d have to go hunt some. That way I could treat Dia to a delicious pheasant roast for dinner.

Dia and I went out to the courtyard.

Over the last ten days, we’d been splitting up the work and recording a wide variety of new spells and rules.

If it hadn’t been clear before that Dia had a talent for magic, it certainly was now. I had been fairly self-assured in my skills of analysis, but Dia had discovered way more rules than I had.

“This should complete the spell you’ve been working on, Lugh,” she said, passing me a note with something scribbled on it.

“Amazing. This is exactly what I was looking for. You’re really good at this,” I praised.

“I’m your big sister, after all!”

That doesn’t have anything to do with it , I thought. It would’ve been annoying to have Dia get upset with me, so instead I merely nodded and added the new piece to the formula I’d been working on.

“If we can pull this off, it’ll dramatically increase the value of magic,” Dia surmised.

“Yeah, you’re right. This long-range magic with explosive firepower should have very low fuel consumption. It’ll be incredibly convenient,” I said.

Before long, it was time to test some magic fit for assassination.

The spells we were developing were extremely dangerous, so Dia and I decided to perform our tests on a hill behind the estate.

After exchanging a nod with my mentor, I performed an earth elemental conversion and began my incantation. I produced iron from thin air, morphed it into the shape of a cylinder with a handle, and then carved out the inside of the cylinder.

I continued to chant, loading the cylinder with a tungsten bullet.

The first step was complete. Next, I performed a fire elemental conversion and once again began to chant. I filled the inside of the cylinder with fire mana until…

BOOM.

An explosion propelled the bullet forward. The little projectile spiraled rapidly thanks to the rifling I’d carved into the barrel.

Instantly, the bullet broke the sound barrier. With impressive aerodynamic stability, it traveled four hundred meters, where it knocked down a large tree.

“Wow, it worked! This new magic we’re developing could change the way people use spells. You can reach distances  impossible with a bow, and it’s so accurate and so strong! This is amazing!” Dia exclaimed, excited.

“With this kind of range, you won’t have to worry about being defenseless during the incantation,” I said.

Up until now, incantations had to be cast relatively close to your opponent. But with this firing range, you’d be able to safely chant from a distance where not even arrows could reach you.

Dia performed the same incantation that I had and tried firing a bullet.

“Whoo-hoo! I hit that boulder! It was massive, but it was blown to pieces.”

“Let’s practice a bit more. It’s clearly powerful, but we need to ensure that it’s accurate, too. I prepared these for that purpose.” I motioned to a large collection of bullets I’d created in advance.

Making a bullet every time you wanted to fire was inefficient. Instead, it was better to have many of them ready and simply load them by hand before propelling them with the fire explosion. This method was sure to work better in battle.

“Good thinking. Let’s practice!”

We became engrossed in practicing this new magic. I felt like we got more accurate the more bullets we fired. Reducing recoil was going to be important for improving accuracy even further.

Now that we were capable of firing bullets using fire magic, my first goal was complete.

There were some complications, though. It was important that you used mana to increase your physical strength right before the explosion, and the timing to do so was precise. Without enhanced strength, you wouldn’t have the power necessary to keep the muzzle from rising. It was likely you’d also be knocked to the ground by the force of the explosion.

The barrel of the gun greatly resembled that of a matchlock, but the firepower and accuracy were on another level. Magic combustion was capable of much more force than gunpowder ever was, and even more important, my bullets were of a much higher quality.

The harder a bullet was, the denser a surface it’d be able to penetrate. Tungsten was one of the hardest metals known to man, giving it a huge advantage over iron bullets.

Back in my original world, tungsten was often used in the  shells of tanks, and it could easily cut through steel plates.

The aerodynamic shape of the bullets I’d made gave them low air resistance, and the rifling ensured high accuracy as well. There was no denying this was incredibly useful magic, but I was still going to need more firepower if I was to kill the hero.

My current level was probably more than enough to handle the average mage, but against the almighty hero, it was unreliable at best. That guy’s abnormal strength meant something on this level wouldn’t even scratch him if I shot him at point-blank range while he was napping.

With that in mind, I’d prepared something even stronger for today’s test.

The fundamentals were the same, but this magic was on a different scale. Such spells would be impossible to use for someone without my mana capacity.

“Lugh, what is th—? HUUUUUUUUH?”

My new magic began to take shape.

First, I produced the barrel. This one was much larger than the matchlock-sized original. Its size was around that of a tank cannon.

The barrel was about two meters long and very thick. Even the sight of it was intimidating. As it was impossible to carry by hand, it would have to be placed on a pedestal and staked into the ground.

The cannon was too big to create all at once, so I was forced to make it in three parts and combine them together using a transfiguration spell.

Next, I produced the ammunition that the cannon would fire.

Much like the barrel, the bullet was also quite massive. It ran around 120 mm in diameter, a common size for tanks. That was roughly fourteen times as long as a bullet used in a pistol. It was enormous, roughly the size of a milk bottle.

I took a deep breath, then cast the fire spell. When the smaller gun had fired, I’d tried my best to repress the force so the barrel wouldn’t rupture, but that wasn’t an issue with this cannon. Even if I put all my strength into the explosion, the barrel was thick enough to withstand it.

The inside of the cannon surged with a force that put the gun to shame.

“Dia, cover your ears,” I instructed.

“O-okay!”

A thundering shock tore through the air, and the cannon fired. Such firepower made the gun look like a child’s toy by comparison.

Despite being fixed in place with spikes, the cannon ended up being propelled backward, tearing up the ground along the way. The impact left a crater on the surface of the mountain where it landed.

“I knew that increasing the mass of the bullets and strengthening the explosion would create force on another level…but I didn’t expect it to be this strong,” I said.

In my previous life, I’d operated tanks and even fired shells, but this was an even greater power.

Unfortunately, I knew this still probably wouldn’t be enough to kill the hero if he used mana to withstand the explosion or if he had some kind of skill that enhanced his defense at all times.

Even then, there was a chance it could kill him if I caught him off guard. That meant I now had a card to play that could get the job done.

“What the heck do you plan on shooting with this?! This is clearly overkill!” Dia shouted.

“I might one day have to face an opponent who can’t be killed without this level of force,” I answered vaguely.

I checked the barrel and immediately spotted a problem. A crack had formed in the metal. I’d thought it would be thick enough to prevent that.

Should I use something other than iron for the barrel? …No, there’s no metal that makes more sense. Tungsten is much harder than iron, but it’s brittle. I need a hard metal with high tenacity.

This was going to be a problem if I could produce only raw metals. Alloys and processed metals would surely be stronger. As I  thought about it, I reasoned that it should be possible to create alloys using magic. Were that true, I would have access to even more durable materials.

“I got the force I wanted, but there are still a lot of kinks to work out,” I explained.

“This is ridiculous… But firing that thing looked like it felt really good,” answered Dia.

“Want to try it?”

“Hmm, I hate to admit it, but I can’t. It would be impossible without your insane level of mana,” Dia said reproachfully. She wasn’t wrong; firing the cannon did consume a very large amount of mana.

“I now know the issues I need to work on with this magic. All right, how about some practice?” I proposed.

“Okay! Hmm-hmm-hmm, if I use magic like this, those barbarians won’t stand a chance!”

I wasn’t sure exactly what Dia meant, but it seemed there was some sort of enemy she wanted gone.

“Oh yeah, Lugh. You haven’t named these spells yet,” she added.

“Right. I’ll call the one you’re holding ‘Gun Strike’ and the big one ‘Cannon Strike.’”

“I’m not really sure what those words mean, but they sound cool!”

I could feel my past intuitions with firearms returning as Dia and I continued firing practice until she ran out of mana.

With no wind interference, it should’ve been possible to strike an immobile target from over three hundred meters away without issue. Normal assassination jobs would be a piece of cake with a gun like this.

In this world, where the concept of a gun didn’t even exist, being sniped from a distance would seem impossible to defend against.

“Only four more days… I want to stay here and do this forever,” Dia muttered solemnly.

It was true—there wasn’t much time left with her. There were still a number of things I wanted to do before she left.