Hel led Niv out of her alchemy workshop and into a spacious chamber within the underground shelter.
At the center of the room stood a massive circular black altar. Its surface gleamed with golden light; on closer inspection, one could see that a layer of orichalcum plating about a centimeter thick had been mounted atop it. The altar's base material was no less impressive—it was constructed from Black Tortoise Stone bricks, a material reputed to be unbreakable by anything short of the Saint tier.
An altar built at such cost was, of course, no ordinary object.
Yet its true value did not lie in the Black Tortoise Stone bricks, which were classified as military-controlled materials, nor in the orichalcum plates that even Saint-tier powerhouses would fight over.
Its real worth lay in the alchemical formation engraved upon those orichalcum plates.
Tiny, tadpole-like alchemical runes formed the foundation of the array, while layers of geometric frameworks divided it into countless large and small regions. Across this massive formation—over ten meters in diameter—were densely packed geometric structures and alchemical symbols. Only the very center of the array, along with seven nodes positioned along its outer edge, were left with a bit of empty space.
This was the charging array Hel had previously prepared specifically for the forbidden-spell greatsword.
Charging a holy artifact was an exceedingly troublesome task. Back when Hel had first created that forbidden-spell sword, the charging process alone had taken more than ten days.
At that time, she still needed to refine arrays to gather ambient elemental energy from her territory, and there had been no pressing need to improve efficiency.
But now things were different.
The start of the school term was fast approaching, and Hel still needed to locate the Recovery Witch, as well as the Harvest Witch and the Growth Witch—about whom she had no leads at all.
Those last three pieces of the puzzle firmly pinned her outside, leaving her no chance to retreat back to Heim and quietly build up strength.
Because of that, she needed to resolve everything here before school began.
The solution was simple in concept: increase the strength and scale of the alchemical array so that it could rapidly channel energy and forcibly inject it into the charging target.
This array had been built precisely for that purpose.
The very center of the formation was the charging node where the target would be placed. The seven smaller nodes along the perimeter were designated for energy sources.
As for energy supply, there was no need for concern.
Along the walls of the room stood more than a dozen racks, each stacked with various kinds of energy crystals—ordinary elemental crystals, less-than-ideal mana crystals, and elemental ores.
But the majority of them were desire energy.
Refined desire energy, combined with ordinary desire energy, occupied roughly half of the shelving.
The properties of ordinary desire energy hardly needed explanation—it was comparable to standard elemental crystals, with even worse versatility.
As for refined desire energy, while it carried numerous drawbacks, its one undeniable advantage was sheer abundance.
Each refined desire energy crystal was about the size of a thumb and stored in small boxes, ten crystals per box. Despite their modest appearance, every single crystal contained ten Niqi worth of mana—equivalent to a lowest-grade seventh-tier elemental crystal. (Note: Niqi is a unit of magical energy in the story)
Fully charging this grimoire would absolutely not require more than ten seventh-tier elemental crystals. Otherwise, it wouldn't be a holy artifact—it would already qualify as a demi-artifact.
And in this room alone, there were a thousand such refined desire energy crystals.
Energy was not the issue.
Speed was.
And whether the summoning grimoire could actually absorb desire energy.
Hel placed the summoning book at the center of the alchemical array, then took a small box of refined desire energy crystals from one of the racks.
She selected seven crystals one by one and placed them onto the seven charging nodes along the array's edge. Then she stepped back two paces and gently placed both hands on the rim of the formation.
Alchemy was a form of magic that did not require mana—but that did not mean it was unrelated to magic.
Most alchemical runes were, in fact, variants or derivatives of magical runes. Among them were also many ancient runes that had long been discarded.
These were symbols that allowed far more convenient control over elemental energy, but due to their abysmal performance in actual combat, they had been abandoned.
Alchemists, however, were different.
Unlike mages, they did not need to constantly streamline their spell structures to achieve rapid casting. They could afford to spend enormous amounts of time in pursuit of better effects.
It was the difference between a prototype machine and a mass-production model.
And the formation Hel had constructed here was a top-tier array born of her peak alchemical expertise.
The materials invested were no less than those of a holy artifact—perhaps even more—and in terms of performance, it surpassed the vast majority of holy artifacts outright.
The instant Hel activated the array, brilliant red light erupted across its surface.
But in that same moment, the isolation barrier installed within the room rose simultaneously.
This, too, was an alchemical construct—one of the ways alchemy could be applied in combat, and likewise an auxiliary technique to alchemy itself.
As such, the isolation barrier was highly adept at suppressing alchemical light. After a brief flicker, it pressed the red radiance down, confining it to the surface of the array alone.
It now looked like a thin veil of energy draped over the formation, completely enveloping the summoning grimoire at its center.
Time passed—about the span of a cup of tea.
Suddenly, streaks of emerald-green light began to flash from the summoning book, while the pink energy swirling around it started to dissipate.
Yet, just as when Hel had previously used desire energy to cast spells, something peculiar occurred.
Even after the desire energy had fully dispersed, the green light emanating from the grimoire still carried faint traces of pink.
The bizarre scene made it seem as though the summoning book—having had its fill of desire energy—was now striking a "this book has used you up" pose as it kicked the desire energy out.
The pitiful desire energy, however, appeared to leave behind one last act of defiance before being expelled—as if it were determined to put on a final display of "old man ghost-fire" in front of the soon-to-arrive Flower Spirit Mother Tree, its would-be "mother-in-law."
And so, within that half-green, half-pink radiance, a small tree woven from countless flowers emerged above the summoning book.
Hel hadn't even begun chanting the summoning incantation recorded in the grimoire, yet the Flower Spirit Mother Tree had already leapt out impatiently.
Whether this was because too much desire energy had been infused, triggering a passive effect of the summoning book—or because the Flower Spirit Mother Tree had sensed the malice of desire energy—was anyone's guess.