After the Fall of the Demon Race, Reincarnated as a Demon Girl - Chapter 4

Renith took a few idle steps across the shattered remnants of the fortress. In the open space before her, two layers of luminous barriers rose—the outer one, a radiant shield of holy light, had been set by Alegria. The inner one was her own.

The first barrier would be trivial for Philof to dismantle. As a spirit born of Alegria’s power, she could effortlessly bypass her creator’s seals and dismantle them from within.

Assuming, of course, Alegria had no intention of stopping her.

The inner barrier, however, forced Renith to exert real effort. This was no ordinary mage’s work—it was beyond mortal comprehension. Had she not understood the underlying mechanics of the spell matrix, she wouldn’t have dared approach it with such confidence.

Once both barriers were dispelled, Philof’s voice chimed in.

“Page 79 of the Codex. Earth Magic—Pulse.”

An invisible ripple spread outward from beneath Philof, revealing hidden potions, scrolls, and other artifacts buried beneath the rubble. Despite two centuries of neglect, they remained perfectly preserved—as expected of relics crafted by the System, a divine artifact.

From the trove, Renith retrieved a short-handled staff she had buried long ago, along with a selection of useful potions. The rest were promptly stored away in the Codex’s dimensional space.

With the staff in hand, Renith could now manipulate mana with precision, enabling spells previously beyond her reach.

The moment she grasped it, she tapped her throat lightly. When she spoke, the voice that emerged was Arund’s.

“Hmm. Ahem.”

Philof immediately clapped a hand over Renith’s mouth. “Lady Renith, your current appearance… doesn’t suit that voice. If you dislike your natural tone, perhaps something more neutral? Though a younger register would be preferable—ah, never mind. This just sounds… odd.”

Renith frowned but silently conceded the point. After a moment’s contemplation, she cycled through two voices that had left indelible marks on her memory: one, naturally, was Alegria’s. The other belonged to a fearsome general from the Demon Army she had once faced.

That warrior had single-handedly scattered three members of the Hero’s Party. Yet, in the end, she had fallen—defeated by Arund in a duel.

The curse she unleashed with her dying breath haunted Arund for decades. If asked who left the deepest impression on Renith from the Demon Army, even the Demon King paled in comparison. The Demon King brought momentary despair—she brought endless suffering.

“Using your voice… is a tribute to your mastery of magic.”

Clutching an assortment of bottles, Renith strode deeper into the Demon King’s castle.

Philof still found the chosen voice too mature, but before she could protest, Renith marched ahead without so much as a backward glance—as if ready to abandon her on the spot. So, Philof swallowed her complaints.

……

The Demon King’s Seat

If one sought a place to rapidly amplify their power, the Demon King’s final resting ground was ideal. The sheer density of mana here was staggering—the Demon King’s lifetime of accumulated energy had seeped into every inch of the land beneath the castle.

The closer one got to the heart of the fortress, the thicker the mana in the air became. It was almost as if one could see the remnants of that world-shaking power from two centuries ago.

So why hadn’t human mages flocked here to train?

The answer was simple: Every mage who tried had gone mad.

The mana here carried a curse—one that amplified the darkest corners of the human psyche. Those who trained within emerged changed, their personalities warped beyond recognition. By the time humanity realized something was wrong, it took years to hunt down and contain the afflicted.

(Incidentally, this discovery was made around the year 740 of the Chaos Calendar.)

During that era, a captured demon’s blood was distilled and fused with its mana, creating a potion designed to kill mages—“Spellbane Needle.”

That same year, a Grand Archmage’s research revealed that demons were immune to the corrupting influence of the Demon King’s residual mana. Their physiology differed from humans—what was lethal to humans was harmless to them.

And now, Renith was a demon.

For all she knew, this “poison” might be a feast for her new form.

“Two hundred years, and this mana remains untouched. Unusable by anyone… except me, now that I’ve become this wretched creature.”

…..

The Throne Room

Inside the grand hall, Renith—clad in a light-blue mage’s robe—leapt onto the Demon King’s massive throne, kicking off her shoes and tucking her bare feet beneath her.

With a solemn gaze, she surveyed the empty chamber.

“Hey, Philof. Do I look like the Demon King?”

Philof shut her eyes and shook her head.

“Not… even a little, Lady Renith.”

“Fair enough.”

The day after the Demon King’s defeat, Hertis—freshly healed—had perched on this very throne with the same demeanor, looking down at everything below. He had grinned and asked Arund:

“Well? Do I look like the Demon King now?”

Arund had stifled a laugh. How could the righteous Hero ever resemble that monster?

The Demon King’s colossal frame had demanded a throne of matching scale. Renith, by contrast, could sit cross-legged with room to spare—her slight form almost dainty against the seat’s enormity. She even had space to casually arrange her potions and scrolls beside her.

With a tear of parchment, she activated a barrier scroll, enveloping herself and Philof in an invisible shield. Then, uncorking a vial, she downed its azure contents in one gulp.

“Three months, Philof. Until then.”

Her eyes slid shut as she plunged into the deepest meditation.

Only when Renith’s breathing steadied into utter stillness did Philof collapse onto the dark tiles, trembling uncontrollably. A primal fear gripped her—one she couldn’t suppress.

“It’s… too similar. No. No. Lady Renith is Lady Renith. She couldn’t possibly be…”

Swallowing her unease, Philof retreated into the Codex.

…..

Three Months Later

Renith opened her eyes—right on schedule.

Her gaze, once sharp, now shimmered with a clarity like still water. The mana clinging to her had transformed as well, dense and heavy, a far cry from its former state.

In this world, warriors, mages, and clergy lacked rigid hierarchies, but broad classifications existed.

Once, warriors were ranked by their mastery of “Qi”—beginners dubbed “One Qi,” with each additional strand marking greater prowess. But after the Hero’s Party felled the Demon King, this system faded, replaced by an imperial “Peerage System.”

Now, warriors were granted noble titles commensurate with their strength—a move meant to incentivize talent. In theory.

In reality, within a century, coin had corroded the system. Titles no longer reflected true power.

Mages, however, adhered to an older, more stable framework—one established by the Second Hero, founder of the Mage’s Tower:

• Apprentice: Minimum mana capacity; basic spellcasting.

• Journeyman: Proficient in multiple spells.

• Archmage: Can perceive mana flow, sort particles by attribute, and cast refined spells.

• Magister: Mana particles orbit them passively, forming a “spell membrane.” Can craft barriers, magical tools, or potions. Must master 30% of recorded spells in their field.

• Grand Archmage: Must invent an original spell and master a forbidden incantation. Expertise in 50% of their field’s spells.

The clergy’s hierarchy was simpler: The closer to the divine, the greater the borrowed power—and the steeper the cost.

…..

The Mage’s Eye

Renith now possessed the mana density of an Archmage. The ritual had gifted her the “Mage’s Eye”—the ability to see and categorize mana particles.

Tapping her forehead, she dimmed her vision until only the floating motes remained.

Red for fire. White for wind. Brown for earth. Pale blue for water. And…

Gold?

Since when were there five elements?

That faint gold—if she wasn’t mistaken—was Alegria’s holy light. The blessing of a Saint.

When had she been blessed?

At the moment of her death, perhaps?

But that wasn’t the strangest part.

Amidst the golden particles swirled traces of black—a shade she’d only seen in demons. Alegria had named it “Umbra.”

And now, as a demon herself…

Did this mean she could wield their magic without the Codex?