To put it simply, it was a fact that Ancient Dragon leather did not leak mana to the outside.
Because its affinity with magic was too high and its capacity too great, no detectable amount of mana escaped Reiko’s body.
"Hmm. Usually, about a hundred times more than this should be leaking out," Jin mused.
One could also say that the efficiency of her mana usage was just that high.
"Wait... could it be...?"
To confirm a sudden flash of inspiration, Jin led Reiko over to the window.
"Reiko, try casting a spell... let's see, a Light Ball will do. Fire it outside."
"Yes, Father. Understood."
Nodding at Jin’s instruction, Reiko extended her right arm and began the incantation.
"Light Ball...!"
"Whoa!"
Calling it another sun would be a bit of an exaggeration, but a ball of light so blindingly bright it begged the description was launched into the sky.
"F-Father, I am so sorry...!"
Reiko was mortified that she had startled Jin. However, Jin wasn't angry. He was shielding his eyes, lost in thought.
"Hmm... Mental waves are the same as mana waves... So Ancient Dragon leather shouldn't let mental waves leak out either... and yet..."
Jin asked her another question that had come to mind.
"Reiko, are you receiving a supply of free ether?"
He had wondered if, since mental waves could not penetrate the Ancient Dragon leather, she might also be unable to gather free ether from the environment.
"Yes, I have no problems at all."
"I see... Hmm."
Jin fell back into deep thought.
"Certainly, if the leather didn't allow free ether to pass through, even an Ancient Dragon would probably suffer from an ether deficiency..."
It was hard to imagine that such a massive creature could be supported solely by the free ether contained in the air it breathed. It was more likely that the skin and the internal magic core also converted it into energy.
Furthermore, free ether was theorized to be particles much smaller than protons or neutrons. In other words, even Reinforced leather could be permeated by it.
"So there's no problem with taking in free ether."
Since this was a fact, Jin decided to treat it as a premise for the time being.
"The properties of dragon leather can be controlled with one's own mana waves... and since mana waves equal mental waves, maybe she can adjust it with her own will?"
Having reached that hypothesis, Jin decided to put it to the test.
"Reiko, fire a Light Ball one more time."
"Understood... Light Ball."
"Trace."
This time, Jin didn't look directly at the light; instead, he tracked the flow of mana. And what he discovered was...
"Aha... So the free ether taken in by the skin was at work."
Essentially, the Ancient Dragon leather serving as her skin was synchronizing with Reiko’s mental waves to draw in free ether, converting it into mana and boosting the magic.
"This looks like it’ll be difficult to adjust..."
It was a problem if the lowest-output magic became maximum-scale. It was like wanting the flame of a match but getting a flamethrower instead—actually, it might be even worse.
Even though Reiko primarily focused on physical combat, this was a serious matter. If she couldn't use Craft Magic properly, she wouldn't be able to assist Jin in his workshop. Reiko understood this herself and wore an uneasy expression.
『My Lord, I believe it would be best to solve these issues one by one.』
Laojun offered advice to the troubled Jin.
"Ah, yeah, you're right. First..."
First was the issue of individual recognition, exemplified by the Warp Gate.
"Why was she able to use the Warp Gate earlier?"
At the moment, Reiko’s body wasn't emitting enough mana for an individual to be identified.
"...Ah, the pendant."
A pendant hung from Reiko’s neck. Jin had crafted it and given it to her when he made the Protect Rings and other magic tools. Since it carried Jin’s own magic pattern, it had inadvertently ended up acting as Reiko’s identification tag.
Currently, the only parts of Reiko’s body not covered by Ancient Dragon leather were her eyes, the inside of her mouth, and her nostrils and ear canals. The tiny amount of mana leaking from those areas was not enough to trigger individual recognition magic tools.
"Well, that part should be fine one way or another..."
At worst, she could just carry a magic tool like the pendant. The real problem was the control of magic power.
"Can you consciously suppress the boost from your skin?"
"Yes, I will try."
Reiko fired a Light Ball for the third time.
"Oh, it worked."
This time, a normal Light Ball flew out.
"See, Reiko, you can do it if you try."
However, Reiko’s expression remained grim.
"Father, the control is extremely delicate. I do not believe I would be able to manage the adjustment in an instant or a crisis."
"Hmm, I see..."
Being too powerful could indeed be a burden.
"Speaking of control, there's always a staff..."
Magi used staves to increase directivity and convergence, making magic easier to control. Firing magic directly from the palm or similar parts simply didn't offer very good convergence or focus.
"In that case, maybe it would be good to have something like a pole?"
Thinking about it, that seemed more efficient. Jin extended his arm straight out. His index finger pointed at a target. Inspiration struck Jin as he stared at the tip of that finger.
"Claws!"
"Father?"
Because the brooding Jin had suddenly shouted, Reiko looked at him with a puzzled face.
"It's the claws, Reiko. If we make your claws into magic poles, you should be able to fire magic from there."
With that said, Jin began to sift through the leftover Ancient Dragon leather.
"Here we go. I can use this."
From among the scraps, Jin found a piece that appeared to be from the Ancient Dragon’s leg.
"Look, this part is thick and hard. Let's use this for the claws."
The claws would be linked to the bones of the fingertips on the inside, becoming poles to fire magic. Just in case, he upgraded her toenails in the same way.
"How is it, Reiko?"
"Yes, I shall try it."
With those words, Reiko reached her hand out the window and fired magic.
"Light Ball."
A perfectly normal Light Ball was released.
"Father, this has actually become easier than it was before!"
"Then it's a success."
"Yes, this is amazing."
After trying various things, it turned out that as long as there was even one 'pole,' controlling the power of the magic became easy.
"In other words, until now, it was difficult to control because the mental waves meant for control would diffuse across the entire skin. But if there's a pole for activation, you can just concentrate on that spot, making it easy to manage."
Jin felt a wave of relief.
"Now then, shall we practice a bit to get you used to that control?" Jin suggested.
"Practice, Father?"
"That's right. Basically, you'll be accumulating control data."
『My Lord, do you have something specific in mind?』
Laojun also seemed unable to gauge Jin’s true intentions.
"Yeah, isn't there a highway connecting the Klein Kingdom and the Kingdom of Egerea that passes through the Former Leonard Kingdom? I was thinking it might be good to secretly maintain that road."
This would bring profit to the Klein Kingdom and the Kingdom of Egerea—both of which Jin was on friendly terms with—and it would serve as a check against the Celuroa Kingdom, which he didn't have a particularly good impression of, even if they weren't exactly enemies.
"Besides, I want to make it possible to reach it from Kaina Village in the future, too."
『I see. So it isn't strictly a charitable venture. In that case, I think it would be a fine idea.』
"Alright, let's head out tomorrow morning."
Before they knew it, the sun was already setting. At that moment, Saki and Elsa arrived. Judging by what they were holding, it seemed the two of them had been making something together.
"Hey Jin, so you were here. Have you been working on something?"
"Yeah, actually..."
Jin gave the two of them a brief explanation.
"...I see, I can understand that theory," Saki said.
"Hmm, to think there were such side effects..." Elsa noted.
"...That's why I told you it would be better to consult Jin-nii, Saki-nee."
"Heheh, it's fine. There's meaning in thinking for yourself!" Saki countered.
Jin directed a question to the two of them as they bantered.
"By the way, what were you two doing?"
Without answering the question directly, Saki unfolded what she was holding to show him.
"Take a look at this."
It was a leather vest. And as for its material...
"Ancient Dragon leather... I see."
"Heheh, that's right! I came up with the idea, and Elsa made it. It's a gift for you, Jin!"