Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ Volume 10 Chapter 21

I went to [Despair] Demon Lord Belial's dungeon.
I had expressed to him that I wanted the two of us to talk about something. He then replied that he would love us to meet in his dungeon. Within his crystal room, to be more specific.
I, who wanted to retrieve the listening device, found his proposal convenient. At the same time though, I couldn't help but think that there must be a reason he proposed to use his crystal room.
"We've been going on a lot of trips lately and that's made Kuina quite happy! Kuina will make sure Oto-san'll be safe this time as well."
"Yes, I have nothing to worry about as long as you're by my side."
It was unkind to Kuina, but I wasn't going to rely on her protection this time. For the events ahead, I prepared some other things.
Furthermore, because Kuina was so easy to ready, I decided to keep her in the dark. It was just so much safer for her to know nothing than to make her act like she knew nothing.
I'm so sorry, Kuina.
"Alright, let's head off to Belial's dungeon"
"'Kay!"
I instructed a Darkness Dragon to descend and rode it.
Hopefully, we would have a confirmation at last.
◇
We arrived at Belial's dungeon and was then uneventfully guided to his crystal room.
"Welcome, Procell-sama. I've heard of your settlement agreement. As always, a complete victory! To think you could make all those Demon Lords agree to your terms. A feat some, I daresay most, Demon Lords can never hope to accomplish!"
"I didn't make them agree to anything. They offered the terms themselves. In any case though, I'm glad fighting's over. I have no doubt I'll win even if it continued, but Avalon and my monsters might suffer some damage in the process."
In all honesty, that was number one reason I accepted the settlement.
My monsters and my city of Avalon were extremely important to me. I couldn't imagine myself wanting something so much that I would happily put the things and people I love in harm's way.
"Ahh, such confidence. And the might to back it up. You're so magnificent, Procell-sama. Who wouldn't want to be like you? To be strong; to be able to act freely and proudly; to be able to live without compromises… Sadly, that's a life exclusive only to strong Demon Lords. For most Demon Lords, especially those that were born with only B rank medals, the only way they know how to live from the moment they're born is to play along with the whims of those stronger than them."
"That may be true, but if they plan for it enough, they could take down at least one Demon Lord with an A rank medal. My point is, the balance of power can change in an instant. It's not easy, but it's possible."
In fights, the strong doesn't always win. Plans, schemes, tricks, and whatnot could be employed by the weaker side to overcome the might of the other.
It was risky, but the reward of being able to create the other Demon Lord's medal and use their unique skill could be considered worth it.
"Ahahaha. I suppose that's true."
"In the first place, you also have an A rank medal. Why are you talking like you only had a B rank medal??"
To that, Belial did not utter a word back. He only smiled.
However, that smile was completely devoid of emotion. It was as though he was only doing it to mask something.
"Well then, Procell-sama, what is the matter you wished to discuss?"
"Let's not ruin the mood by getting down to business right away. Why don't we update each other while chatting idly like this for the moment?"
"Understood. Everything you say really is a morsel of wisdom. And while we're chatting, let's also enjoy some tea and snacks, shall we? I've been a bit obsessed with black tea recently. Oh, do you know what that is? Fantastic. Well, I guess I shouldn't even have asked since there probably are so many blends coming to Avalon from all over the world. Speaking of those blends, I try a different one each day, yet I don't think I'm close to having tried all of them."
I didn't dislike this "humanness" of his. In fact, I would say I liked it.
"That's a nice hobby you have there. I'd very much like to try out the blend you liked the most."
"Of course. I'll prepare it at once."
While we were chatting like that, I was busy with something else.
The listening device I had planted in this room was intact, but being seen retrieving it would be inconvenient, to say the least.
For that reason, I opted to recover just the recording it held via its data link feature.
In order to listen to the recording without raising any suspicion from Belial, I made use of a bone-conduction-type earphone and a playback device developed by Rorono. And to save time, the playback device had features such as automatic and high-speed data sifting, plus a playback speed of 16 times faster than normal which was still intelligible to me thanks to some training.
…this further proves that even though Demon Lords were capable of guarding themselves against normal and even magical espionage, they couldn't protect themselves from a technological one. After all, one couldn't prepare for something that they didn't even know existed.
At the current technological level of the world, listening devices, video and audio recordings, and data links were several times more mysterious than magic.
"This tea is delicious."
"Glad you liked my favorite."
And so, while drinking tea with Belial, I was analyzing the audio recording of his crystal room. It was several days' worth of data, but thanks to the 16 times playback speed and AI that cut out silent periods, I finished the analysis in less than 30 minutes.
This endeavor revealed some truths to me.
The good news was that Belial was not a traitor.
The bad news was that the one before me was a traitor. This is almost as bad as the worst-case scenario I imagined.
"I think it's time we move on to the main subject. I have something I've been meaning to give you."
"I-is that?"
"Yes, it's my [Creation] medal. I've wanted to give this to you as thanks for giving me your [Desperation] medal, but my doubt of you won over. Now that the members of the anti-Procell alliance have been identified, I see that my suspicions were for nothing."
I smiled and then handed him my [Creation] medal.
It was one of the medals I had reserved for my allies.
"Thank you, thank you very much. With this, I could make a ridiculously powerful monster and be of more use to you."
"Well, you don't have to make it for me, but do please make the monster as soon as you can so that you can make a [Maelstrom] for its corresponding B rank monster. Can you imagine the improvement of even a single [Maelstrom] can do for your war potential? In some sense, that'll be the proof we've become true allies."
Belial nodded.
The strength of an S rank monster made with his [Despair] medal has already been verified through Fallen Angel Raphael. If he, someone who had superior knowledge on the properties of the [Despair] medal, used a third A rank medal for the Synthesis, the monster he would create could be stronger than Raph.
"So, this is the reason you came here?"
"…yes, and to apologize for having doubted you all this time. And now that I've accomplished both, I best take my leave."
I proceeded to stand and turn my back to him.
As though he wanted to stop me through an embrace, Belial also stood up and approached me.
And then…
I felt a cold, solid object pierce through me, followed by searing hot pain and the gushing of my blood.
In other words, Belial stabbed me from the back.
Even if he were to kill me, a new Demon Lord, he wouldn't incur any penalties. This was because when I attacked the [Insect] Demon Lord's dungeon, some of the monsters we attacked were actually under Belial's control. These monsters were originally made by the [Insect] Demon Lord and were only given to Belial, so no matter how much we review our footage, we wouldn't have been able to realize this. We only got this information thanks to our aggressive interrogation of the [Insect] Demon Lord.
"Oto-san! You! How dare you!"
Kuina fired a flaming shot at Belial, causing the latter to hit the wall.
He was still alive, but his face was utterly expressionless.
And then, I heard a voice within my head.
>
It was a voice I had heard before.
After all, whoever it was, it was using my own voice.
"That way of talking… is that you, [Black] Demon Lord? So, you really were behind all these…"
I had suspected an attack would happen at this time.
The settlement offers were too generous, clearly made so that I would lower my guard. After all, it didn't matter to them whatever they offered if they were going to defeat me and take over all my possession in the end.
>
The [Black] Demon Lord was an enemy, but I still had some respect for him. So, when he said the words some small fry would utter, I was more disappointed than vexed.
"Belial… did you take control of him like this too?"
>
At this reply, the corners of my mouth rose.
>
"If you're asking that, I guess you really didn't notice anything at all. Belial has been continuously sending me messages. He keeps on the act like you want him to, but at the same time, he has been giving me hints. He has been going against you. Do you understand? I am not the prey here."
In order for me to not suspect Belial was being possessed, the [Black] Demon Lord likely allowed Belial some control over his own body. Quite ironically, this small amount of freedom allowed him to send me small and subtle hints that made me aware of things.
I wasn't sure this was the case, but after hearing the recordings of the listening device, I was.
>
"You got me there. But let's go back to your question of why I still walked into your trap despite Belial's hints."
From the start, I had suspected that the [Black] Demon Lord was somehow involved in all of these.
Coupling that with Belial's hints, there was no way I would come unprepared.
>
"I guess the saying the only cure for stupidity is death is false. You're proving that even death is not enough to cure it. I mean, to fall for the same trick twice. Let me tell it to you plainly: this body is not real."
◇
When "I" said so, "I" vanished.
And then, another me appeared alongside Aura.
The truth was that there was two of me in the room. One was the real me, the other was a copy made by Stolas's [Omnipresence].
Aura had used her wind to conceal our forms and presence.
"Let's talk about your [Black] ability, shall we? It allows you to slip into the darkest recesses of someone's heart and take control of them. To make it easier to do so, you rile them up anyway you can. Unfortunately for you, you can't rile me up. How could you when you're nothing but a joke. My heart will never darken because of you. So, are you still going to challenge me?"
>
He was coming at me.
This much was inevitable.
His original vessel, Belial, was gravely wounded and would soon die, so returning there was no use. On the other hand, if he were to possess Kuina or Aura who were my monsters, he would have to obey my commands.
According to what I heard from the [Time] Demon Lord, once the [Black] Demon Lord has left his host body, he has approximately 10 seconds to don a new one or return. In other words, the moment the [Omnipresence] copy vanished, the countdown for his life began.
"Procellllllllllllllllllllllllllllllllllllllllll"
I also used my other trump card for this event.
That trump card was the silver watch I received from Dan as the reward for overcoming his trial. It had the ability to use Dan's own [Time] ability. That said, it was an item that could only be used once and only for a short while.
Just moments before he reached me, I touched the silver watch.
The [Time] function I chose was Time Stop. It was a very powerful function. After all, if my time was stopped, I was virtually invincible. I was isolated from any external interference, be it physical, magical, or spiritual.
So, [Black], whose success rate on me was already trivial, now had zero chance of success.
A second later for me and ten seconds later for the world…
"Aura, can you sense his presence anywhere?"
"No, master. He's really gone now. I kept careful watch until it happened."
I see. I'm glad, then. My fight with the [Black] Demon Lord finally came to a definite end.
"Please give Belial treatment."
"He has a 50-50 chance to survive right now…"
"Even so, please try. He has been a great benefactor. I can't simply let him die here."
It was because of Belial's signals that we were able to piece together the truth. Despite being controlled by the [Black] Demon Lord, he kept on struggling.
There was no way my conscience would forgive me if I didn't even try to save him.
Aura took out a container full of Ronove's viscous liquid and poured some into the gaping wound. After various tests, we have concluded that Ronove's viscous liquid had highly potent healing abilities. This along with Aura's healing powers probably made the best first aid treatment.
"Geez, Oto-san, why did you hide it from Kuina?"
"To trick your enemies, you have to trick your allies first, right? If your anger were to show beforehand, he might get an idea of what we know and what we plan to do about it."
"…I understand. But I'm still not happy about it."
I brushed the head of this pouting Kuina.
"Master, the worst part's over, but he's still in danger. For a full recovery, I'll need the equipment we have in Avalon."
"Okay. Then, let's Transfer back to Avalon right away."
Our first priority at the moment was Belial's survival.
To that end, we could leave the explanations to his monsters for later.
Once he has recovered, I should go thank him again. For being a real comrade.