Accompanied by the undead of the former Recapture Army, I returned to the capital via teleportation magic.
I had been uncertain if such a feat was possible, but it succeeded without a hitch. The ability to instantly transport a force of twenty thousand was undeniably convenient. It was a tactic that could be applied to various strategies.
While I felt a noticeable dip in my mana, I was far from exhausted. If I refined the spell formula specifically for mass teleportation, I could likely reduce the consumption even further. In matters like these, a Sage truly proves his worth.
The benefits of my transformation were immeasurable. It wasn't just that my magical output had increased; I was now capable of realizing spells I never would have dared to consider in my previous life. If I am to become an eternal evil, I cannot remain shackled by human limitations. Without growing arrogant, I intended to continue fortifying my position until it was truly rock-solid.
I teleported to the outskirts of the Royal Capital. I didn't return directly to the castle because I had a small matter to attend to first.
I made my way to the Valley of the Dead. There, I returned a portion of the undead to mere corpses and offered them to the valley. It was a semi-instinctual act, a result of following the dictates of the miasma residing in my soul.
The moment I offered the bodies, I felt my power swell. It seemed my Authority had grown stronger. The Valley of the Dead, which had cleared after I first absorbed its power, was once again being shrouded in thick mist.
The valley was the source of my strength. By polluting it with miasma, my very existence was being bolstered. This was a significant discovery. I resolved to offer corpses here frequently.
(I tell myself that I have absorbed the power of the Valley of the Dead. But in truth, perhaps it is the valley that has absorbed me.)
The thought crossed my mind, but it was ultimately irrelevant. It wouldn't change my course of action. I didn't care what means were required, as long as I obtained the power of a Demon King.
As a precaution, I protected the Valley of the Dead with large-scale barrier magic before heading back toward the capital with the remaining undead in tow.
Everything was proceeding smoothly.
The Recapture Army, which had sought a swift resolution, was now extinct. Similar forces were likely mobilizing elsewhere, but once word of this massacre spread, they would surely hesitate. They would realize that numbers alone were no match for me.
From here, they would likely move into a phase of investigation and strategic planning, attempting to analyze my abilities before launching another attack. Whatever they decided, it would take time for them to act.
That was fine by me. As it stood, it was impossible for humanity to subjugate me. This delay would prevent them from throwing their lives away in vain. After all, I didn't desire the total destruction of the world. My only desire was to act as a perpetual threat—a common enemy to ensure humanity maintains peace among themselves.
Unless they launched an offensive, I planned to leave them be for a while. While they made their preparations, I had work of my own to do.
I arrived at the capital while lost in thought. I walked down the deserted streets, dismissing the undead I had acquired during the battle along the way. Having no immediate use for them, I simply let them wander the city.
I continued toward the castle on foot. For some reason, I felt the urge to walk through the cityscape.
Traces of blood stained the stones, and the streets were lined with houses on the verge of collapse. Many buildings were nothing more than charred husks. Rotting food sat in the open, discolored and forgotten. The entire city was desolate, a vivid portrait of a daily life that had been shattered in an instant.
My heart ached, but I felt no regret. This was the path I had chosen.
Dwight Harvelt, the Sage who had once helped slay the Demon King, was dead. The being standing here now was an immortal Demon King destined to repeat the cycle of slaughter. Since I had made a choice from which there was no turning back, it was my duty to see it through. I could not allow the sacrifices of the dead to be in vain.
Occupied by these traces of human life, I eventually reached the castle. I looked up casually and froze.
The walls had once been chalk-white and the roof blue, but now the entire structure was enveloped in a sinister, reddish-black luster. Eerie blue flames flickered in various places. The castle's new aesthetic was so singularly malevolent it was almost a caricature.
(What happened in the short time I was gone?)
Actually, I knew exactly who the culprit was.
I used teleportation magic to jump directly into the Audience Chamber. The room itself appeared unchanged. The moment I sat upon the throne, the doors swung open and Grom entered.
"Welcome home, my Demon King! I was watching the festivities with clairvoyance magic—it was a magnificent display of valor! I was so moved, I nearly shed tears of joy..."
Grom, trembling with theatrical emotion, knelt with a fluid motion. He made a show of dabbing his eye sockets with a handkerchief. The flames dancing in those sockets singed the edge of the fabric.
Was he actually serious? Knowing his personality, it was entirely possible. It was difficult to judge, but I had more pressing concerns. Setting aside my confusion, I questioned the kneeling skeleton.
"What have you done to the castle’s exterior?"
"Ah, yes! I have remodeled it into a residence befitting a Demon King. I have also layered various defensive spells throughout the structure, so our security against intruders is now absolute. Tell me, do you find it to your liking?"
Grom spoke with a tone that practically begged for praise. He seemed immensely proud of himself. Despite his face being nothing but a bovine skull, he managed to convey a staggering amount of emotion. We were both composed of bone, yet our capacity for affability was worlds apart.
"............"
I glanced down at him. Grom was restlessly shifting his gaze. He clearly wanted a compliment. I got the distinct impression that if he had a tail, he’d be wagging it.
While he had certainly taken liberties with the renovations, there was no actual harm done. I didn't have any particular attachment to the original architecture. To be honest, I didn't care what the place looked like.
Furthermore, Grom hadn't just changed the aesthetic; he had drastically reinforced the castle’s defenses. When I scanned the area with detection magic, I found an astronomical number of spells woven into the structure. Anyone attempting to enter without permission would likely be incinerated instantly. The barriers were so thick I doubted an intrusion was even possible.
Even across the entire world, security this tight was a rarity. It gave me a glimpse into Grom's sheer competence and motivation, having set all this up in such a short window of time. His eccentric behavior often made me forget, but he was a terrifying entity. If he felt like it, he could wipe a continent or two off the map—enough to make the extinction of the human race a very real possibility.
In many ways, he was far more like a Demon King than I was.
"I had overlooked the castle's defenses. I appreciate your initiative," I said eventually.
Despite his lack of consultation, there was little to criticize. It was better to acknowledge his hard work.
Upon hearing my words, the flames in Grom’s eye sockets flared with intensity.
"Your words fill me with joy...! My word, all the hours I spent agonizing over the design were well worth it. I, Grom, am honored to be of use to you, my Demon King!"
"I am likewise honored to have such a capable subordinate. However, please consult me before making such changes in the future."
"Understood! This loyal servant would be delighted to offer his intellect for your approval henceforth."
Grom pressed his forehead to the floor. His loyalty was absolute—more akin to religious worship than mere service. I could only offer a dry smile in my heart at his sheer dedication.
"M-My Demon King, we have a situation!"
Two nights later, Grom rushed into the Audience Chamber in a panic. It seemed something significant had occurred.
"What is it? An intruder?"
"N-No, not exactly... At any rate, I believe it would be best if you saw for yourself."
Grom’s tone was uncharacteristically hesitant, as if he were unsure how to categorize the event.
I immediately cast a detection spell over the entire capital. If there was an anomaly, this would find it. Sure enough, I picked up a massive cluster of reactions near the main gates. There were approximately five hundred of them.
They were certainly not intruders; they were gathered outside the gate, waiting patiently rather than attempting to force their way in. It was no wonder Grom was confused.
I crossed my arms and withdrew my consciousness from the spell.
"I see. It seems we have guests."
"How shall we proceed? If you give the word, I shall go and annihilate them at once," Grom said, his aura shifting into something dark and murderous. If I had so much as nodded, he would have vanished to start the slaughter.
"No, I will go out myself. Follow me."
"Ha! As you command!"
Grom instantly suppressed his killing intent and saluted. His mental flexibility was almost frightening. To him, personal feelings were secondary to my orders. His discipline as a loyalist continued to surprise me.
I used teleportation magic to take us both outside the castle, landing on the crest of the capital's outer wall. It was the perfect vantage point to observe the main gate. I stood on the edge while Grom hovered beside me.
Even in the darkness of night, my undead body allowed me to see as clearly as if it were noon.
A swarm of monsters was gathered below. I saw the small, green forms of Goblins and the massive frames of Ogres. There were Orcs with their porcine features and small, dog-faced Kobolds. Among them were Succubi with their twisted horns and bat-like wings. It was a diverse gathering of many different races.
"A formidable host... It is strange that I did not detect them until they were at our doorstep."
"They likely used stealth magic. There is no shame in it; I know who our guests are."
Grom turned toward me, his curiosity piqued.
"That tone... Do you know these creatures, my Demon King?"
"I do. We have a history that dates back to my previous life."
As we spoke, the monsters below noticed our presence. A wave of surprised shouts rippled through the five hundred-strong crowd, sparking a chaotic commotion.
But in an instant, they fell silent. It happened the moment a Succubus standing at the front of the group raised her hand.
Grom stroked his chin, observing the scene.
"Ho. It seems that Succubus is their leader. I wonder who she could be."
There was no reason to keep him in suspense. It was better that he knew.
"She is a Demon who served the previous Demon King," I said, answering the question he hadn't yet asked. "Specifically, she is one of the Four Heavenly Kings."