The royal castle, which stood at the center of the Orbaume Kingdom, was in a state of panic due to the sudden appearance of a massive horde of mice.

“W-what is this? It’s summer already, but I’m getting the chills… Is it just my imagination?” someone remarked.

Someone else suddenly shrieked in terror. “Mice! There are mice in here!”

“Don’t get so worked up over seeing a mouse or two–” began a third, before seeing the mice and screaming.

“What is this huge number of mice?! Are they being controlled by a spell or something?!”

“Calm down, they’re just mice! Maids, get away from them! Civil officials, protect your documents! Someone get the dogs or cats in here!”

Mice were just mice; the city guards or the knights could chase them out and exterminate them – or so they thought.

“It’s no good! No cat or dog can handle this many mice!”

“You’re kidding me, right?! The cats might be of no use, but the dogs have been trained as hunting dogs and guard dogs!”

The cats kept by the city guards and knights were just to keep mice away, but some of the dogs were those trained as hunting dogs to be used by King Corbitt when he went hunting, and the rest had been trained as guard dogs.

But the mice were not fleeing before the cats and trained dogs; they chose to fight them instead. They formed coordinated groups to fight with numbers.

The mice avoided the mouse traps laid around the castle and easily chewed through nets that were supposed to be difficult to cut through even with a sword.

“These are no ordinary mice! We have no choice but to lure them into a corridor and use magic to wipe them out!”

“Wait, we’re going to use offensive magic against mice?! If we damage the artworks–”

“Does it look like we can afford to be worrying about that?!”

The chaos among the knights grew as they found themselves unable to deal with the mice as they wanted, but the Imp Mice led by Tadano Nezumi, tiny Demon King Familiars that looked exactly like mice, and spirits that couldn’t be seen by the people in the castle continued to search for Rikudou.

Using the information they gathered, Vandalieu made marks on his map of the castle.

“Just in case, we’ve searched the sky above the castle, the top of the roof, and the space beneath the roof… He doesn’t seem to be in the upper areas of the castle,” said Vandalieu.

He could declare this with absolute certainty because there was no place in the upper area of the castle that he couldn’t reach and no space that he couldn’t see.

Rikudou Hijiri had made perfect preparations, just as he had in Origin… He had prepared a place where Vandalieu and his allies could never find him, and he was hiding in that place.

In order to find him, Vandalieu and his companions simply needed to find this unfindable place.

Of course, this was not a matter of simple wordplay. The place where Rikudou was hiding was certain to physically exist somewhere. In order to find it, he was searching this castle using spirits that could pass through any wall, Imp Mice that knew every hidden path and every space behind every wall in the castle, and split entities of himself, which would not be fooled by any illusion.

They were leaving subtle coloring on places that had been searched. Rikudou would be hiding in the place that could not be colored.

In order to carry out this search method, he had needed enough spirits and Imp Mice, and most importantly, a perfect map of the castle that showed every secret escape route that wasn’t on the castle’s official blueprints and every hidden chamber that only the royal family knew of.

All of these had come together yesterday. Vandalieu had already contacted his allies, and they were on standby in their designated positions.

“Now then, just the lower half of the castle is left. The predictable answer would be the basement…?” Vandalieu murmured.

The spirits and Imp Mice headed for ground level, and then below it. The maids and civil officials in the castle fled from them as if being chased, while the knights fought hard to somehow try and exterminate the mice without causing damage to the castle.

However, this was not going very well because some of the mages of the royal court were under the influence of Duke Alcrem and Duke Jahan, and because the knights were not willing to damage the castle in order to exterminate the mice.

“Can you not do something about this?!” one of the knights shouted in frustration.

“They’re mice, after all. If I may set the whole castle ablaze, then I believe I could exterminate them,” said one of the mages.

“O-Of course you can’t do that!”

“Not even electricity or freezing air? Then I have no choice but to defeat them with offensive spells, one by one. But I’m afraid my Mana won’t last if I do that. The mice seem to be heading towards ground level, so it seems like it would be wiser to let them go for now and then think of a way to deal with them afterwards.”

“Damn it! Don’t damage the castle to exterminate the mice!” ordered an enraged King Corbitt, who was being protected by bodyguards and knights. “More importantly, make sure there are no intruders seeking to take advantage of this chaos in order to enter the castle! And keep watch so that nobody can carry classified information or valuable pieces of art outside the castle!”

“You lot, follow King Corbitt’s orders! But the thing you must guard most vigilantly is the king and the royal family! It is possible that the enemy is an assassin who is after their lives, not just valuables and information!” Marshal Dolmad told his men. “Come, Your Majesty. We must get you to a safe place!”

If he had noticed that the Imp Mice were monsters, he might have ordered for hastier measures to be taken… Perhaps he would have ordered the mages to cast their offensive spells and the knights to swing their weapons, accepting some damage to the castle.

But he and his men considered monsters to be around a meter long, like Horned Rabbits and Giant Rats. Indeed, there weren’t even any records at the Mages’ Guild of monsters that were so small that they could fit in the palm of a hand.

Even though they believed that the mice were being controlled by someone, they didn’t realize that they were monsters.

“What about the prime minister?! Where is Prime Minister Tercatanis?!” Dolmad demanded.

“I-I do not know!” one of his subordinates stammered. “It is possible that he is still in his office…”

Dolmad made a small noise of frustration. “At a time of emergency like this?” he muttered, suppressing his irritation and holding back curses because of the presence of the knights and city guards.

The prime minister had been behaving strangely as of late… such as his sudden proposal of the use of weapons made from fragments of the Demon King. He had also been staying at the castle for over a month without returning to his mansion, despite not having a tremendous volume of work to do, and he had reduced the number of soldiers that accompanied him for his own protection. There was clearly something different about him than before, but that didn’t mean that Dolmad could simply abandon him.

“Form a unit of five knights and one of the court mages so we can go and rescue him!” Dolmad ordered.

It was possible that Tercatanis had fallen over in surprise upon seeing the mice and hit his head, causing him to lose consciousness. The kingdom would become a laughing stock if it lost its leader because of a bunch of mice.

“Yes, sir!” his subordinates answered.

He led the knights and the mage to go back towards the castle’s upper area, but that movement was heard by Vandalieu as well.

And then, Prime Minister Tercatanis appeared. “Sorry I am late,” he said.

“Prime Minister, where have you been all this time?” asked King Corbitt.

“I was ensuring that no important documents would be lost or leaked in this commotion, which is why I was late to evacuate. I’m very sorry to cause you any concern, Your Majesty King Corbitt,” Tercatanis replied.

“I see. Then that is fine. Let us evacuate outside the castle and then wait and see if the mice will leave.”

“Very well.”

Prime Minister Tercatanis joined the evacuation as if nothing had happened, but Marshal Dolmad had an ill feeling about this. However, although the prime minister’s behavior struck him as strange, all of the prime minister’s behavior had been strange lately.

It probably isn’t important enough to press him about it while we’re still trying to escape from the mice, he thought as he evacuated with the others.

A Demon King Familiar watched Dolmad and the others from the breast pocket of Prime Minister Tercatanis… or rather, the Vampire Zombie Isla, who had transformed to disguise herself as him.

“The king and the others are evacuating more quickly than I anticipated. It seems that it was a good idea to put effort into disguising the Demon King Familiars as ordinary mice for the safety of Tadano and the others,” it said with a satisfied nod.

And then Vandalieu turned his attention towards what he was seeing through another Demon King Familiar, which was currently looking at the real Urgen Tercatanis.

Prime Minister Tercatanis was alone in his office with his eyes closed, appearing to be praying to something. It was unclear as to whether he was requesting Rikudou Hijiri’s aid or whether he was simply reporting the abnormal events that were taking place in the castle, but there were no signs of Rikudou making a move… though it was unclear as to how Tercatanis and Rikudou were communicating with one another in the first place.

“We’ll be continuing our search, but I suppose I should seize you, too,” the Demon King Familiar said.

He gasped in shock as his praying was interrupted. “W-who… A monster?!”

He stared at the Demon King Familiar that had entered his office through the door… the creature with an enormous brain about a meter across, eyeballs, antennae, and insect-like legs, as it approached him.

“Can’t you be a little nicer and call me a stranger instead?” the Demon King Familiar said.

“That’s not possible, given your appearance. You’ll have to make do with ‘monster,’” said Kanako, walking into the office after the Demon King Familiar.

“Fine,” the Demon King Familiar said.

“You! You’re that bard cleric of Vida!” Prime Minister Tercatanis exclaimed.

“‘Bard’… Hmm, it seems that idols are still a long way from catching on,” Kanako murmured quietly.

She was more bothered by the fact that Prime Minister Tercatanis thought she was a bard than the fact that he knew who she was; it made her realize that she was still a long way from her goal.

“Please forget about that for now and hurry things along,” said the Demon King Familiar.

“Are you sure about this? Wouldn’t it be bad to lay hands on this guy?” said Kanako.

“I don’t mind. That would have been true before we carried out this search operation, but now that things have progressed to this stage, it’s only a small problem.”

Harming the prime minister of a great nation was a tremendous crime. If a commoner dared to commit such a crime, they would need to be prepared for the fact that all of their family and relatives would be executed, and even though Vandalieu wasn’t a commoner, he and his companions wouldn’t be able to do this without causing great trouble for Duke Alcrem, Duke Jahan, and even the Tamers’ Guild.

And it could be assumed that if they laid hands on Tercatanis, Rikudou Hijiri would somehow know.

That was why they hadn’t been able to touch him until now, but…

“There’s no way that Rikudou hasn’t noticed the abnormal situation of the castle being overrun by mice, and if we defeat Rikudou, the prime minister will be ousted from his position. If we lose, it’s doubtful as to whether this kingdom will continue to exist as a kingdom. It doesn’t matter either way,” the Demon King Familiar said. “So go ahead. There’s no need to hesitate.”

“Okay, okay. I understand,” said Kanako.

Having heard enough of this dangerous conversation that was taking place peacefully with total disregard for his presence, Prime Minister Tercatanis drew his sword and raised his shield. “Don’t come any closer!”

His sword and shield were the equipment made from Demon King fragments that Rikudou Hijiri had given him.

Taking the appearance of the great horde of mice as a sign that the decisive battle mentioned by Rikudou was about to begin, Prime Minister Tercatanis had deliberately parted ways with the other nobles and the knights so that he could pray to Rikudou and wait for his descent. But it seemed that this decision had been unwise.

This situation was of his own making – one where his social status, which had protected him thus far, was of no use. His sword and shield were the only things he could depend on now.

“My lord, grant me your protection!” he uttered in a short prayer. “‘Triple Slash!’” he shouted spiritedly as he swung his weapon at Kanako.

But with a small grunt of exertion, Kanako easily deflected his sword with her staff.

A moment later, she performed a front kick that struck Tercatanis in the abdomen. Unable to even scream, his eyes rolled into the back of his head as he collapsed.

“I held back, so there shouldn’t be any problems,” Kanako said. “Now then, I’ll be copying this person’s memories with ‘Venus’… Are you sure about this? I won’t be responsible for what happens next,” she said, gripping the unconscious Tercatanis’s head with her right hand and holding the Demon King Familiar’s enormous brain with her left hand.

“Yes, I’m sure. There weren’t any problems during our previous tests, were there?” the Demon King Familiar said.

“I’m just checking, since there normally would be problems… Just how does your ‘Deformed Multiple Souls’ work?” Kanako wondered.

Kanako’s ‘Venus’ was a cheat-like ability that could copy and paste her own memories and emotions as well as the memories and emotions of others. However, in her previous life, repeatedly copying the memories of criminals to herself had affected her own mind. She knew now that this was because copying their memories also copied their thoughts and emotions from those memories as well.

After being reincarnated, she had used her ability more cautiously, and at the same time, she had improved her skill with it. However, no matter how unlikely it was, it would be terrible if Kanako were to adore Rikudou as a result of copying Prime Minister Tercatanis’s memories to herself.

Thus, it had been decided that Kanako would use ‘Venus’ to copy Prime Minister Tercatanis’s memories directly onto someone else – Vandalieu.

Criminals that they had captured had been used in experiments, being given drugs to force them to relax. Kanako had tried copying their memories of that relaxation, and after several trials, they had concluded that it was possible, although it took some time. And copying memories on subjects other than Vandalieu – other criminals – had resulted in all of the subjects’ memories and minds being affected, with some even gaining the ‘Mental Corruption’ Skill.

“Well, here I go… Hmm, as always, it feels kind of bumpy and mushy, and it’s hard to paste the memories,” Kanako said.

“I know I’m asking a lot, but please do your best,” said the Demon King Familiar.

As Kanako actually tried pasting Prime Minister Tercatanis’s memories on Vandalieu, there was more of a burden on her than on him.

“Of course I’ll do my best. It’s also a little bit like I’m avenging myself, too. Not that I have that much of a grudge about it!” said Kanako as she focused on her task.

Meanwhile, the Imp Mice and spirits were continuing their search.

They went from the castle’s middle floors to ground level, and finally underground. The map of the castle was gradually being filled in with color as the searched areas were marked.

King Corbitt and Isla, disguised as Prime Minister Tercatanis, left the castle, and they ordered the mages of the royal court to wait for the mice to come out so they could deal with them all at once.

The Imp Mice and the spirits searched underground… even the secret escape routes. But they still couldn’t find their target. The spirits passed through physical obstacles to reach the spaces the Imp Mice couldn’t, and the Imp Mice searched the places spirits couldn’t enter because barriers had been placed around them. Places that couldn’t be reached by either were checked by the Demon King Familiars.

Finally, the entire map was colored in.

Could it be that Rikudou had left Tercatanis in the castle and escaped somewhere? Vandalieu wondered.

But a moment later–

“We cannot go into this floor,” one of the spirits reported.

This spirit was in the deepest underground chamber in the castle; there should have been nothing human-constructed beneath it.

Thus, the Imp mice had been running around the floor of this chamber, looking for hidden mechanisms, but the spirits hadn’t thought to go through the floor to search further below.

This discovery was a coincidence, caused by the fact that the search was being carried out by hundreds of thousands of spirits, and one of them had simply happened to bump into the floor.

“This floor is also impassable,” another spirit reported.

The Imp Mice squeaked in excitement.

“Hmm… Let’s try physically chipping away at it,” said a Demon King Familiar.

Immediately after this discovery, they all began examining the floor. A barrier had been put up, but not outwards against the floor. It was being cast from within… in other words, from further underground. And although the floor’s surface was ordinary stone, once it was scraped away a little, it gave way to a monster’s carapace that was harder than steel.

This made it all but certain.

The small Demon King Familiars used their front teeth like rock drills to break the carapace, revealing a hole… the entrance to a Dungeon.

“I see. Rikudou Hijiri was able to create a Dungeon. And not only that, but he seems to be cleverer than I expected, creating this Dungeon’s entrance in the floor of an underground chamber,” said Vandalieu, who had teleported to the scene alongside Gufadgarn.

“Indeed. It is exceedingly embarrassing that I, the Evil God of Labyrinths, did not realize this,” Gufadgarn said.

They were surprised by Rikudou’s cleverness. Every Dungeon that had existed up until now had always appeared with a wall or door as its entrance. There were no Dungeons with its entrance in the ground like a trap hole.

And not only that, but the entrance had been completely blocked. Ordinarily, it was impossible to block a Dungeon’s entrance – or to be more precise, it was possible to do so, but monsters would break the blockade down from within before long.

Dungeons where only weak monsters spawned, such as E-class Dungeons, could be blocked for long periods of time using steel. Of course, if a Dungeon was sealed in this way and left alone, the monsters would continue to grow in number and the Dungeon would evolve, causing its difficulty class to increase. Eventually, stronger monsters would spawn inside, and they would break the steel down to escape into the outside world.

It would make sense if Rikudou had created a low-class Dungeon to hide in while hunting monsters like Horned Rabbits inside.

But Vandalieu picked up one of the broken fragments of monster carapace. “If this Dungeon is capable of spawning monsters that have carapaces as hard as this, then it’s likely that Rikudou will destroy the seal on this Dungeon as soon as we take our eyes off it, but…”

He suddenly stopped mid-sentence and made a noise of displeasure. Kanako had succeeded in pasting the memories of Prime Minister Tercatanis, and the memories from the past few months played in the back of Vandalieu’s mind as if they were his own.

“The situation may be more serious than we thought. To think that he would be reincarnated in a body created from more than thirty fragments of the Demon King,” Vandalieu murmured.

“That many… Is it not likely that Rikudou Hijiri has already lost his sanity within this Dungeon? I find it difficult to believe that anyone other than you, great Vandalieu, would have their minds still intact after doing such a thing,” said Gufadgarn.

A single fragment would cause even a Pure-breed Vampire, a being that was considered a demigod, to lose their sanity if they kept it activated for long periods of time. It was hard to believe that Rikudou Hijiri would be able to withstand more than thirty.

It was possible that he had made no moves thus far because he had already been completely taken over by the Demon King fragments.

“That may be the case… But let us be careful,” said Vandalieu.

He gathered the spirits that had been searching the castle close to him once more, and put Tadano and the rest of the Imp Mice inside his shadow. And then he stepped down into the Dungeon that Rikudou had created.

He found himself in a Dungeon floor that looked like a temple, with numerous enormous pillars standing in rows. The moment his feet touched the floor, the layout of the Dungeon’s floors appeared in Vandalieu’s mind due to the effects of the ‘Labyrinth Creation’ Skill.

“Something is wrong. This Dungeon is E-class. Even the Boss is Rank 3, Rank 4 at most. There is no way that the monster who produced that carapace would spawn here,” Vandalieu said.

“Precisely. How impressive that you have realized this right away – and I would expect no less from the man who has defeated me once,” said a familiar voice in a leisurely tone.

A moment later, the Dungeon entrance that had been above Vandalieu’s head closed.

“Impossible. He can erase the Dungeon’s entrance?” uttered Gufadgarn, with clear astonishment in her voice.

There was a rule that all Dungeons must have an entrance. This rule was absolute, and it could not be broken even by her, the Evil God of Labyrinths. Even she did not know why this rule existed, but despite her countless attempts in the past, she had been unable to create a labyrinth with no entrance.

“I haven’t erased it. I have moved it so that it’s no longer on the first floor, but the bottommost floor instead. From your perspective, it’s as if you’ve had the first floor and the bottom floor reversed,” Rikudou’s voice said.

But even Gufadgarn was incapable of manipulating Dungeons in such a way.

“How did you acquire such an ability… This was impossible not only for me and the Evil God of Demon Castles, but even for Guduranis himself,” Gufadgarn murmured.

“Improving my skill has been something I’ve always been good at since my previous life, you see. Now then, I will have to excuse myself, but I’ve left plenty of other elaborate surprises for you in this Dungeon. Please make sure to enjoy them as much as you can. Now then, I shall bid you good day.”

And with that, Rikudou’s voice vanished.

Although the location of the Dungeon’s entrance within the Dungeon had moved, it remained in the same place in the outside world. If there had been someone peering into the Dungeon from the underground chamber in the castle, they would have seen Vandalieu and Gufadgarn vanish into the hole, then witnessed a man whose entire body was jet black, as if it were made from ebony, emerge from within.

“It seems that I have succeeded in confining him. Given the elaborate surprises I left behind in that Dungeon, I’m sure it will take some time for him to escape,” Rikudou Hijiri said to himself, his lips bending in a twisted smirk.

When creating a Dungeon to hide and train himself in, he had first created a low-difficulty, E-class Dungeon as a prototype. And on the bottommost floor of that E-class Dungeon, he had created an A-class Dungeon.

He was capable of creating a Dungeon within a Dungeon. Like creating a Dungeon with no entrance, this was a feat that was impossible even for Gufadgarn… and this one was likely a feat that she had never even attempted.

This was something that he had become able to do after learning about the fundamental truth about Dungeons from the Demon King’s memories.

The Demon King Guduranis had been a monstrosity that possessed tremendous power, but at the same time, he had also been a mage comparable to Ricklent, the Genie of Time and Magic.

His memories… and his knowledge, combined with Rikudou’s intellect and creativity, had made it possible for Rikudou to improve his skills within a short period of time.

The Dungeon he had created inside the E-class Dungeon was A-class in difficulty. It had just a hundred floors. That wouldn’t be enough to even fatigue Vandalieu, let alone defeat him. But he had taken many measures to ensure that Vandalieu would not clear the Dungeon so easily.

“Now then, in the meantime… Hmph!” he grunted, looking up at the ceiling.

Two holes appeared in his chest, one on the left and one on the right, and whirlpools of compressed air were unleashed from within towards the ceiling.

With the Demon King’s nose, he had created the most powerful nasal breath in existence… a pair of air cannons. With enormous power, the air swirled like a tornado reaching for the heavens, destroying the ceiling of the underground chamber and creating a single straight hole that stretched all the way to the royal castle’s roof.

Rikudou leapt up through the hole, then hovered above the castle.

King Corbitt and those evacuating with him shouted in astonishment and terror at the destruction of part of the castle and the appearance of this jet-black silhouette.

Pleased by the sight of those cowering before him, Rikudou floated above the castle and searched for Vandalieu’s companions. “Let’s take this opportunity to get rid of as many of his fighting forces as possible to make him lose his composure, and secure some hostages while I’m at it. If I cast the ‘Death Delay’ spell, they’ll last for a few hours even if they’re decapitated. No, I suppose it would be better to kill them and take their souls captive instead.”

Even if he did this, Vandalieu’s allies would function perfectly fine as hostages if Rikudou threatened to break their souls.

In reality, Rikudou was unable to break souls due to the curse that Rodcorte had placed on him. However, Vandalieu didn’t know that, and there was no need to stupidly tell him.

Once his advantageous position was secured, Rikudou would maintain that position while stealing and absorbing the Demon King fragments from the enraged Vandalieu. Because he possessed fragments of the soul of the Demon King Guduranis, he was certain that he would be able to steal Vandalieu’s fragments.

The only concern was the actions of the Five-colored Blades and Asagi’s group of reincarnated individuals. Heinz, who was capable of summoning the heroic god Bellwood upon himself, and Asagi, who possessed the ‘Mage Masher’ ability which could erase magic of any attribute – including the death attribute – were problematic for Rikudou, even now.

If they were to work together and fight against him, he wouldn’t have the time to take Vandalieu’s companions as hostages.

But I suppose there’s no need to be that cautious of them, is there? Rikudou thought.

Even at a time like this, it seemed that Alda, the God of Law and Fate, hadn’t ordered the Five-colored Blades to work with Vandalieu and his companions.

Rather than having Heinz work with Vandalieu, who would likely stab Heinz in the back at the first chance he got, Alda would prefer that Rikudou and Vandalieu fought against each other first, then have Heinz defeat the one that survived.

There were also the other inhabitants of this world, but the only one that Rikudou needed to be wary of was Randolf ‘the True,’ and the rest were riffraff.

“Now then, first of all, I’ll capture Kanako Tsuchiya, who is near Tercatanis, and the one who’s disguising themselves as Tercatanis, and–”

Despite Rikudou’s certainty that he was already walking the road to victory, he stopped mid-sentence, astonished as he sensed a reaction from ‘Danger Sense: Death.’ But despite his astonishment, he immediately twisted his body evasively.

Even so, he was unable to completely evade the beam of light that had been fired from the royal castle, and he let out a scream of pain as the skin on the side of his torso down to his waist was scorched.

“I’m sorry to interrupt you while you’re acting all leisurely, but I’m also present outside your Dungeon,” said a voice.

Rikudou turned to see the face (?) of a Demon King Familiar resembling an enormous brain, poking out from the window of Prime Minister Tercatanis’s window. It seemed that the beam of light had been fired from its eyeball; its burnt, collapsed eyeball fell and Kanako inserted a new one in its place from behind.

“Y-you bastard!” Rikudou roared, his face twisting in anger more at the humiliation he had suffered than the actual damage.

He immediately tried to counter-attack, but found himself unable to do so as he was forced to avoid the ‘Death Bullets’ that were suddenly fired from directly in front of him.

“And it’s also possible to have Gufadgarn open a teleportation gate for me using my split entities on the outside as a marker. Not that it was simple to do so,” said Vandalieu as he showed himself.

In one hand, he held the Staff of Five Sins in which Fidirg resided, and in the other was a small, half-eaten Demon King Familiar. Behind him was Gufadgarn, who had activated her transformation equipment.

“You never act according to my plans, do you!” Rikudou snarled.

“When you execute a plan, it’s a given that not everything will go according to that plan. But I’ll be destroying and devouring you before you get used to that fact,” Vandalieu said.