This would be the last day that Dia would teach me magic, and in the evening he would pick me up.
　She was testing the culmination of our research.
　That is magic to create an alloy.
　Until now, the magic to create metals could only create single element metals and not alloys.
　But by modifying the matter transformation technique, he succeeded in mixing multiple metals together.
　The significance of this is very great.

For example, there is a metal called titanium.
　It has almost the same hardness as iron, but weighs about 60% less. It has a very high melting point and is resistant to heat.
　In addition, it has excellent corrosion resistance. It's a metal that doesn't rust and doesn't corrode, which is a good thing.
　........However, if it is the standard of the first world, it is not reassuring that the hardness is only as hard as iron. However, the hard metal is not sticky and brittle, or heavy and superior to titanium.
　However, a titanium alloy can increase hardness and sharpness while retaining its advantages.
　To be specific, vanadium and aluminum are added. And by doing so, it becomes Beta Titanium.
　The hardness is nearly doubled, yet it is light, resistant to deterioration and sticky. Beta Titanium is even called the high end of knives when used in harsh environments.

Right in front of you, you can see the titanium, vanadium, and aluminum created by witchcraft and brought together by magic.
　Success. The titanium alloy, beta titanium, is completed as desired.
　It is further transformed to create a knife. I wrap the skin around the handle and hand it to Dia.

"Dear, this is the result of our magic.

Dia slashed at a nearby tree.

'It's light, and what a cut. If we can make and hand out swords with it, our soldiers will take their fighting ability up a notch.'

As expected of a noblewoman, her perspective is different from that of an ordinary girl. And the fact that the idea is the first thing that comes to mind means that her territory must be an environment where she is always aware of the battle on a regular basis.

You should probably not do that.

At any rate, this was an age when poor quality iron was becoming the mainstream weapon of choice.
　If it was known that it was possible to make such an excellent sword, everyone would want it.
　In the past, I was so excited that I described a pure titanium knife as a magic sword, but that was a bit of an exaggeration.
　However, this is a true magic sword.

''If you ask me, that's true... but can't we just trustworthy knights, just the three of us?　They are all very tight-lipped, and I want them to use good weapons. .... so that you don't die on the battlefield.

To not die. The person you care about needs a strong weapon to survive. ...I know that feeling, and I'm a little jealous of the knights who think so much of Dear.

'No matter how trustworthy the knights are, they have someone they can't lie to. The secret will definitely leak out. As I told you before, the new sorcery we created together should be a secret. [Shooting] too, only if your life is in danger if you don't use it.
Yes, I will!

Dia nodded persistently and chanted in imitation of me, but failed to smelt the alloy.

'Oh, why?'
Maybe I don't have enough power of imagination. But unlike creating a product, when you're making an alloy, it's important to have an image of how the metals will change into each other and how it will be completed.

In the case of transformation, the image of the surgeon is important instead of out-of-the-box magic. Unlike transformation, which is just changing shape, making an alloy requires an understanding of chemistry.

'That's impossible for me. I don't know how to mix them together to make a strong metal...''
I'd love to tell you, but it's a very long story, starting with the basics of physics and materials. Yeah, that'll take a month.

A month is a month, assuming you have a brain as smart as Dear. If you're not Deere, you'll see five times that period.

'Ugh, I'm going home today.'
Did you get an extension?
"If I could, I would and I would ask you to do it again and again. But it's not working. I still want to work with Lug to create magic.

I'm a little glad to hear you say that.

...so we're going to do a service.
　I created more titanium alloys and fabricated them into three swords. A sword that cuts well, is strong and light. It is made into a straight sword, the most common type of sword in this country.
　As a bonus, the swords were also fitted with scabbards. It's just titanium because it doesn't need to be sharp.

The knife and the three swords I gave you are just gifts. You and I will have to come up with an excuse for how you got them. Maybe we can get your father to help us. Even Dia's father would be suspicious if he brought back the magic swords from Touahardé territory, and he would probably contact him. He said that his daughter might have stolen it without permission.
'Yes. Maybe your father would do that. I'm very glad you took such good care of him by making him a sword. Lug is a good boy.

I hug the three swords with joy.
　It's the reason why you have magic power to hold three swords that are quite heavy even if they are 60% iron.
　Even if you don't consciously clothe yourself in magic, a certain amount of magic power always covers your body.

''........This is a courtesy. If Dia wasn't my master, I wouldn't have been able to use my magic so well. Thank you.''
Thanks to me. If I hadn't met Lug, the idea of creating magic would never have occurred to me. I've come to love magic much more than I ever have. I'll make lots of new magic when I get home. When we meet again, Lug will write all the formulas for me.
That sounds like a lot of work. But I'll do it. I can't wait to see the magic Dia makes.

I'm sure they'll make some interesting magic with a completely different idea than me.
　If I know that, I'll become even stronger.

It's not fair to teach you only me, so you'll have to teach me the magic you've created, too.
''Well, I'll make a magic that will surprise Diah.......You know the eleventh magic that Diah learned the other day. With that, I think I can make a magic that's four hundred times more powerful than [Bombardment].

There's still a lot of work to be done at the theoretical stage, but once completed, even my instantaneous magic power release is feasible, and a strategic level magic that is four hundred times more powerful than [bombardment] will be completed.

''........That's already transcends even the ritual magic that takes a hundred people to perform. But it's very exciting. I've been excited for the rest of my life since I met Rouge. I don't want it to end today. I promise it's not going to end today.

Dia holds out her fingers.
　They linked their fingers together and Dia laughed.

I thought it was cute.
　I'm sure this is the kind of love I didn't know I had the first time around, or the feelings of longing.
　I want to be with her, and my heart tightens at the breakup.
　I'll get each of these emotions in my second life.
　I'm sure that's the normal happiness I've been seeking.

◇

In the evening, we had a slightly early dinner.
　It's Dia's farewell party.
　There's a row of feasts that my mother and I have worked so hard to make. She has prepared the gratin that she liked best in two weeks, and Dea is the first to scoop it up with a spoon, giving me a melting smile.

'Dear Dear, thank you for bringing our son up to this point,'
'I have the power to do it, but Lug is a genius. I've never been jealous of a child before.
'So the rogue has a talent for magic too? You have a nose for it.

My father laughed good-naturedly and tipped his wine.

'Well, Uncle Kian, I actually picked up a sword when I was exploring the mountains with Lug. Lug said I could take it home as a souvenir, but do you really think I should take it home with me?

After that, we discussed it together and decided to tell my father about the plot.

Oh, you have a sword in the mountains. Can I borrow it for a while?
Yeah, go ahead.

Pulling the titanium alloy sword he received from Dia from the sheath, my father nodded with a light shake.
　My father would be able to see the true value of a magic sword made of beta titanium with that alone.

''Ho, there were some interesting things buried in the pile, weren't there? ........And it looks like it's still buried in the mountain. There might even be another mountain buried in it.''

The intonation in the second half is a bit peculiar.
　I take that intent and I reply.

'Father, there are more buried in that mountain. Let's look for them next time. But it's the only one buried in that mountain. I'll make sure of it.
Well, it's just those mountains. All right, then. You can give it to someone important, Lady Dear.

...By the way, to translate what you just said, my father is convinced that I built it and asks if I can make the same thing, and if I'm the only one who can make it.
　So I replied that I could make it and that I was the only one who could make it.

My father is the only one who can't deceive me in any way, so I won't hide anything from him.
　Besides that, I had a calculation that if there was a problem with this sword going to Vikone, my father would stop it from going to him.

'Wow, you're a rookie, giving a girl a gift. It's not a good idea. You're cute, Diah.
"...Mother, please don't do that.
I won't stop. Lately, Lug-chan has been getting more and more sassy, and this is the only time I've been able to take her down. Do you want to be my child, Dear?
Well, shit, you know, I think it would be nice if that happened.

Deere slumped in embarrassment. My mother is saying a lot of things at Dia's words, getting even better.
　It's not that I don't have the same intentions.
　I'm still just a kid, but eventually I'll have Dia....
　Dia will grow up to be a beautiful woman, and she's excellent. She and I will be able to develop new magic much better together.
　And as strong as I am, it's not enough for me to be the best at killing heroes.
　You'll need a team. There's only so much I can do on my own.
　I need Dia for that.

'I think I'm too quick to do that, though. Anyway, it's nice to have a friend in Lug. I was worried about her because she wouldn't go out there.
Father, don't you think that makes me sound like a dark child?

It's just a point of reflection. My time outside of training and study, I'm constantly holed up in my study or practicing on my own.
　My personal specs had improved, but I may have a problem forming my communication skills.
　From now on, in my free time, I should go out and try to socialize with kids my own age.

'Yes!　I'll be your rogue friend. I'll send you letters when I get back to the estate, and I'll come to see you as much as I can.

My mom and dad are looking at me and Dia, smiling.
　It's a little blistering.
　This warmth is real, but it won't be the only thing.
　There's something I've been thinking about for the past two weeks.
　What it meant that my father had called Dia. It was true that Dia was an excellent teacher. But there was no way that father would call that bomb of a nobleman from another country for that reason alone. It's something worth the risk.
　Inevitably, it's worth it to have me and Diah meet at this point in time to get to know each other better.

Thus, the last supper was over.
　Afterwards, as we are having tea, a servant appears and tells us that he has been picked up.
　We go outside.
　Dia gets in the carriage.
　Slowly the carriage starts to drive away.

'I'm having so much fun!　I'll definitely be back!

Deere exclaims, peeking out of the window.

'Yeah, I'm waiting too,'
And please take this!　Don't forget about me!

Saying that, he threw the pendant that was always hanging around his neck.
　It was a necklace with a transparent crystal on it, and inside the crystal was a glowing purple magic power.
　I know this because I saw it next to me many times. This is Dia's magic power.
　You gave me a foul stone filled with magic power. You said you could never give it to someone from another territory.

''I'll never forget it!

I shout.

'And I'm asking you now to promise to do whatever you said you would do then. If I ever feel like I really need to see Lug, you must run to me!

That's pretty reckless.
　Still, I'm not going to hesitate.

'I promise!　I'll be there when you do!

After a bit, the carriage was out of sight.
　For the past two weeks, I've gained magic and developed it further.
　But it's been a time of gaining something much bigger than that.
　Now, let's keep at it.
　I have to create enough magic to surprise Dia when we next meet.

........Well, when should I go to see her? Normally, I wouldn't have a chance to see Dia for a few years.
　I don't like that. I need regular exchanges of ideas with Dia for researching magic.......and I miss her too much.
　According to my research, it's roughly 320 km over two mountains to the Vicone territory.
　It's not impossible for me to travel a long distance, even if it's me, to secretly slip through the border and enter Vicone's territory without anyone noticing, sneak into the mansion and meet Dia. It would even be the best training for an assassin.
　As soon as I'm strong enough, I'll go see her when I'm ready.
　That's something I never would have done the first time. But I like it that way. I'm not just a tool to follow orders, you know? I do what I want to do, because it's my choice.