Luke's life became one of alternating between chiseling and resting, around ten minutes each to avoid willpower fatigue. For days, he kept worried about Sakura, who hadn't come back ever since the clan head had summoned her.

A male nurse came frequently to feed him, change some bandages, check on his injuries, and change his... diapers. It was a shock to realize he was wearing one, and a shame to do his stuff on it, but it was better than having something stuck into him for him to relieve himself. The nurse suggested using a potty too, but Luke didn't want to shit in front of anyone else, especially not on camera.

The camera was one of those small black domes and was visible by the window. He always asked the nurse to cover it to take care of him, and the man used bandages to do so. Luke also asked about Sakura, but the nurse claimed not to know anything about her, and kept silent unless talked to. The man obviously had been instructed not to reveal anything, and Luke decided not to make things difficult for the person who took such great care of him.

He dealt with the worry for Sakura and shame of being taken care of like a baby by focusing as much as he could at his runes.

Two days after getting kissed for the first time in his life—what a great moment!—he finally finished the mana runes in his core.

The first rune had been the ownership rune.

It made the mana touching it his. Currently, he could only use control mana directly touching his soul's "skin" or millimetrically close to it. Using mana he owned would let him push it a couple inches away from him before he lost control over it. That was required to cast spells, and thus, to become even slightly useful.

The second rune was the permanence rune.

It's form was three concentric squares with a central cross, and a dot in the middle of the cross.

Mana was always stagnant unless someone exerted their will upon it. After Luke had finished with his mana core and had multiple channels connected to his core, mana would have many ways of leaving his body if he moved around. It didn't matter if the mana was his; it would stay right where it was in relation to the environment as his left. It would be just like moving a sieve through water and finding out only a little water was came with it.

A mana user that couldn't move around was just a sitting duck waiting to get attacked and die. The permanence rune solved that. The mana touching it would stay glued to it, and thus move around with the mage, simple as that.

The third rune was the pull rune.

It resembled an asterisk with a missing line and, half circle below, and a full circle surrounding it.

The pull rune would passively pull mana for Luke. For now, it was almost useless, as it couldn't affect anything beyond itself. It still increased the mana concentration ever so slightly as it kept pulling, though not as much as the next rune.

The fourth rune was the condensation rune.

It comprised three concentric circles with very specificly positioned dots bridging them together, and was quite hard to make.

The condensation rune, as its name implied, made mana thicker and, at very, very higher levels, almost liquid. His mana core—hell, his entire soul—was only so big, so condensing the mana was a way of working around that limitation.

And the final rune was the purification rune.

It was the most complex one, two curvy waves with a vortex in between, and multiple lines of different sizes coming out of it like a sun drawn by a child.

Luke could only control so much mana at once. Condensing it didn't change that; even if the mana in his soul became liquid-like, when he tried to use the mana, it would automatically "vaporize," and he would only control as much "gas" mana as he could. Thus, the way around it was to make the mana purer.

Those were the most glaring differences between mana and other energy sources that followed the laws of physics known by humankind. Mana runes weren't really that different from electric circuits or computers, but science couldn't explain how energy could be refined into something purer or be condensed.

Luke's memories didn't tell him what were the impurities mana could accrue either. He also couldn't feel anything of the kind with his Mana Sense. Yet, the fact remained that mana could be purified, and the purer the mana, the more powerful it became.

The purification rune was the main reason most mana users had only one mana core. The stronger it became over time, the purer the mana it could produce. For a rune to become stronger, mana users had to focus on it, and as a rule of thumb, their focus couldn't be split into multiple runes. Therefore, if there were two purification runes for them to improve, one in each different mana core, it would take double the time for both to reach the same level of purification as one would've taken.

Dividing their attention meant effectively making themselves weaker at a set time compared to how strong they could be if they had focused on only one rune.

It also made little sense to do that because eventually, as the runes grew stronger, they would not only affect his mana core, but also his entire soul. Even his mana channels would then be used to store pure mana, and he had to make them grow thicker anyway, which would also increase their storage capability.

In the end, a mana user had limited time, limited willpower—fatigue was still a thing—and had to prioritize where to invest those two resources.

Those five runes could be different, but his memories told him they were the most effective. Everything he was doing was the optimal solution. In fact, many would kill for such a seemingly simple knowledge.

And it wasn't just the knowledge of what to do, as in which runes to inscribe, but also the how to do it, or how they looked like. Information on what some runes did was precious in the tower and hoarded by most mana users. Most organizations had at least a few dozen people drawing random forms all day and checking how mana reacted to them, just so they could find a new rune. And he knew so many of them...

Forget killing, some people would wipe out entire races, including their own, if they could get access to the knowledge in his head.

That thought gave him pause. Maybe Sakura had been right all along. He couldn't just disclose everything he knew, or the human race might very well be all but erased from existence just so such knowledge wouldn't spread. Forget the demons, even a powerful enough human could kill almost everyone, then restart the race from scratch with a harem of their choosing while hoarding the knowledge and living like a kind of god. Knowledge was power, and the people in power always suppressed knowledge to prevent their opponents from also growing powerful.

He quickly thought of a solution, which he would discuss with Sakura—who had kissed him, by the way—later.

Now though, he had something much more important to do: his first mana cycle.

And then, he would cast his very first spell.

The mana cycle started with focusing on the pull rune.

Runes worked passively, but focusing on them made them immediately more effective, and over time, their passive power would also grow. Luke would go through many such cycles in the future. In fact, mana users were known for working on their core runes anytime they had the chance.

Currently, all his runes could only affected the mana straight up touching them. As he focused on the pull rune though, it became more effective, and he felt the mana a couple inches around it getting pulled closer. Soon, all the mana that could accumulate without getting condensed had done so, and he took all the mana he could and moved it to the next rune.

Luke could only move the mana touching his soul's surface. That was also true for holes in his soul, and he could only impart his will on the mana touching his core's walls, not anything in the center. Not until his ownership rune's influence grew larger.

So, naturally, the rune he moved the mana to was the ownership rune.

He focused on it, which also increased its influence to a couple inches, and all the mana around became his. In fact, just by focusing on it, more mana became his than what he had brought from his pull rune, to the point the latter might be considered worthless.

However, Luke was planning for the future. This would be the cycle he would keep doing, and the pull rune would get more important as it grew more powerful. He needed them all to grow stronger, so he didn't ignore a single rune now, no matter how useless they might be.

Now that the mana was his, he could push it around freely around his mana core, so he moved it to the next rune, purification.

The mana shrunk in quantity as it was purified, until it became less than ten percent its impure, raw form. When the purification rune grew stronger, it would make the mana amount decrease less, probably because it learned to differenciate between what was impurity to be thrown away and what had to be kept. It was anyone's guess where the impurities went to.

Like all runes, it was almost useless now. The mana amount had decreased by a lot, but its purity had increased by almost nothing. Luke would be better served by not purifying his mana, but doing it was also an investment on his future.

The next step was moving the purified mana to the condensation rune.

A couple minutes after getting affected by that rune, the mana volume became barely one percent compressed. He kept the mana touching that rune for a while longer, and it kept compressing it, until its volume had decreased by around ten percent while keeping its mass. That rune's condensation speed would increase as it grew stronger.

Speaking of which, energy had no mass, so it was another point in which mana didn't behave in a way that humankind's understanding of physics could explain.

Finally, he moved the mana to the last rune, permanence.

While he was focusing on it, its area of influence also increased to a couple inches. However, as soon as he removed his focus, it would go back to only affecting the mana touching it, and most of his mana would be lost as he moved—not that it was an issue now, of course.

Luke needed to improve that rune, and the rest of them really, for them to passively cover his entire mana core. Only then would he become more than a mana user and get in the ranks of a mage. All mages were mana users, but not all mana users were mages. Right now, he was a novice by tower standards.

And that was it, one cycle complete.

After his mana had shrunk in amount and volume from getting purified and condensed, there was still some space left in his permanence rune even in its passive state. It wasn't empty space, as raw mana was touching it, but mana that had gone through the cycle was the only one he could use to cast spells. Therefore, he started the next cycle.

Each cycle took about twenty minutes. After the third one, he had enough mana for the next step toward true power:

Casting his first spell.