The interior of the tower was soon lit up by small torches lining the walls. Truthfully, there was no real reason to have torches when they were being filled with 'Fire' spells, anyway. In the first place, the most effective way to light a room had to be by using 'Light' runes, so his teacher was definitely just doing this to look cool.
"Hold on."
"What is it?"
"Before we do this, can I go to sleep first?"
Jane immediately found a clean-looking part of the ground and laid down on it. While his teacher looked on incredulously, he fell into a deep sleep.
---
'Did I really just go to sleep inside an abandoned building, right next to an untrustworthy man?'
Jane had yet another reason to sleep properly from now on.
He couldn't tell how long it had been, since the inside of the tower looked more or less the same. His teacher was sitting on a chair nearby, with his arms crossed and his eyes closed. His brows were furrowed, perhaps having been like that for hours.
"You're awake, right?"
Calex quickly opened his eyes, which were incredibly bloodshot.
"Yes. Shall we continue on with our lesson?"
"Sure..."
He didn't object, suspecting that too much snark might genuinely get him killed at that moment.
"Are you familiar with captive soul cores?"
"Why would I... No?"
His teacher reached for something on the table. It turned out to be a small locket. He flipped it open to reveal a mass of condensed mana inside.
"The methods to make one are a little advanced, so I won't teach them to you yet, but creating magical tools using captive soul cores is decent practice for runes, and great practice for engraving."
"So you want me to make a tool that'll conceal my mana?"
His teacher snapped the locket shut, hiding the mass of mana from view.
"No, such a specialized tool is outside of your current capabilities. You'll be making a generalized concealment tool, instead."
If the situation wasn't so precarious, Jane would've made a joke about his teacher using a tool to kidnap people. Regrettably, he had to keep his mouth shut this time.
"So, what's the rune for 'Concealment'?"
Calex gave him a look before grabbing a sheet of paper and a pen. He quickly scribbled down a rune, and handed it to Jane.
"By the way, this rune can't be refined. You have to make it right the first time."
"It'll conceal itself?"
"Exactly. Well, that's enough hints from me. Your house is due mostly north from here— you know how to navigate using the stars, right? Goodbye."
Before Jane could say anything, his teacher activated a spell and disappeared. However, with his increased perception, he could make out a little of the runes used.
'Sneaky bastard, he just hid himself.'
Jane glared at the spot where his teacher had disappeared, then turned his attention to the locket on the table. It was too early for that to come into use, however. Wasting no time, he began practicing 'Concealment'.
---
Quickly enough, his runes reached the point where he could no longer perfect them further. They were most likely a little under the quality of his mainstays, but it would simply be too difficult to improve runes which disappeared as soon as he made them. Once they disappeared, control over the mana in the rune would grow more difficult, and eventually he would see the remnants of the spell begin to return to his soul core.
'Wait a second. How do I even engrave things?'
"Teacher? I know you're there, and you know I know you're there, so can you come out?"
His teacher materialized right behind him.
'Seriously, why does this guy always appear behind me?'
"Anything sharp works, as long as you imbue it with mana."
Imbuing objects with mana had no real effects on their physical abilities, but it did enhance them in some ways regarding magical attributes. A knife that wouldn't normally be able to pierce through a defense spell might be able to do it when imbued with mana.
Jane personally found it to be a complete waste of time, but nonetheless found a sharp-looking utensil and gathered mana into it, not bothering to form any runes. The mana seeped into the structure of the scalpel he picked up, giving it a strange quality.
He looked back at his teacher, but the man had already went into hiding again. Seeing no point in further delaying, he flipped open the locket and began working.
The process of engraving was really quite simple. All one had to do was scrape away the outer layer of a Manaheart in accordance to the runes they wished to take effect. However, Jane realized that this particular engraving would be a little more difficult.
For the maximum effect, he would have to engrave as many 'Concealment' runes as possible, but inscribing a single complete rune would cause the entire locket to become incredibly difficult to work with. That was because it would immediately disappear upon completion. However, he had an idea to combat this.
At each of the axes of the spherical soul core, he engraved a near-complete 'Concealment', leaving out only a single stroke. Then, he engraved three near-complete runes in each of the eight regions between the first runes. Jane took a moment to memorize the positions and orientations of all of the runes. Honing his focus, he started to complete them.
The moment the first rune was completely inscribed, the entire locket vanished from sight. However, Jane did not falter in the slightest. He continued inscribing, watching the table become hazy, then even his hands become hard to make out. By the time all thirty runes were inscribed, Jane could no longer make out any part of his body. He smiled, although nobody could have noticed he was doing so. Reaching out based on his memory. he closed the locket and draped it around his neck.
'Oh, my god. I might really be a genius.'
As if agreeing with him, a hand landed on his shoulder from behind.
"What the—!"
Jane jumped, knocked into the table, and promptly fell down. He tried to orient himself on the floor, but he couldn't tell where any of his limbs were touching.
"How do I turn this off!?"
"My disciple, I admit you might be talented at engraving runes, but did you seriously not think about what it would mean to have 'Concealment' runes constantly active?"
"So, it's a failure, then?— ow, ow..."
His teacher sighed slightly.
"Feel around your locket for a switch. It should be close to where the chain is attached."
Jane began patting down his body on the floor, searching for the familiar outline of the locket. He soon found it, and ran his hands along it's surface. Finding an odd texture underneath his fingers, he exerted pressure, and—
'Wow, this is a really embarrassing pose.'
He could once again see himself sprawled out on the floor.