After Ten Millennia in Hell

The inside of the mountain, which should have been nothing but dirt and rocks, had been artificially hollowed out.

[Yawn.]

A demon, Belphegor, yawned while looking down at the people lined up.

He was sitting on a chair that looked like a wheelchair and frowned as if he didn't like what he was seeing.

[Why was the plan pushed up so much?]

One could feel the annoyance in his voice. He complained while lying in his chair as if he were too lazy to get up.

"I heard that something unforeseen had happened."

A low voice came from a man covered in bloody bandages—it was a voice as unpleasant as grating metal.

Belphegor looked at Crimson Fiend, the person standing next to him.

[Like what?]

"I heard that the demon king appeared."

Bam!!

Belphegor sprang up after hearing what he said.

[Wh-What?]

Crimson Fiend's eyes shone when Belphegor got up.

'Belphegor stood up?'

He'd never seen someone as lazy as Belphegor on the continent of Huan and Earth combined.

He always sat in a mobile chair because he was too lazy to move around despite having a perfectly working body. He also never took the time to listen to the reports that the apostles regularly gave him.

He had put off reconstructing his body back when only his soul was left within his Hell Armament, so it was not difficult to imagine how lazy he was. Belphegor was so lazy that he couldn't even be bothered to properly absorb the Demonic Origin that allowed one to acquire Divinity. Despite this, Belphegor had gotten up.

[That is… complete nonsense.]

Belphegor's face paled, and he trembled immensely. He looked so pathetic that one couldn't see the dignity of a prince of Hell. Fear had even echoed in his voice.

Crimson Fiend frowned.

"Is the demon king that strong?"

To be honest, he had almost heard nothing about the demon king after all the time he had been working with the Demon Cult. He had just heard that Satan, Belphegor, and Mammon had struggled against him in the past.

[Is he that strong? That strong, you ask?]

Belphegor laughed at the absurdity of Crimson Fiend's question.

"Is he not but a mere human in the end?"

Crimson Fiend had been a human before becoming a demon after learning the demonic arts, so he knew better than anyone else that a human body was fundamentally different from a demon body. He had to put forth painstaking effort to gain the power the demons had since birth.

'It took a very long time.'

He circulated the demonic energy inside his body.

To stand on the same ground as those who had been born with the destiny of being an absolute being called a 'prince of Hell,' he had to spend a thousand years practicing the demonic arts while absorbing the blood of tens of thousands of humans.

'But even still…'

He had not been able to surpass Satan—he hadn't been able to go beyond the innate limit of a human.

[A human… you say?]

Belphegor's eyes trembled.

He extended his hand and grabbed Crimson Fiend's collar.

[Listen well. He is a monster. A crazed monster!!]

A human?

Who would dare ignore the demon king just because he was a human?

No, to be honest, Belphegor had also ignored him at first.

Demon king… To be more precise, before the demon king had come to be known as that and when he had declared war against all princes, Belphegor had ignored him because he couldn't be bothered with it.

But then, all seven princes of Hell had lost.

They were all devoured by one monster.

[Aaaahh, how could this have… H-He died for sure! I felt it!!!]

He'd felt the demon king's energy vanish when he was torn apart by the dimensional wall.

Although his soul had been pathetically stuck in his Hell Armament at the time, Belphegor had clearly felt it. He had even been thrilled by the fact that he had finally been freed from that lunatic, but… he was alive?

[A-Aaaahh.]

Belphegor trembled in fear.

Crimson Fiend clicked his tongue while looking at him.

'He reminds me of a martial artist who has met the Heavenly Demon.'

Where he used to live in Huan, there was a being who ruled through immense fear.

The Heavenly Demon…

Those who met that being were devoured by fear and lost their minds, just like what was happening to Belphegor.

'The demon king is on par with the Heavenly Demon?'

Nonsense.

Crimson Fiend shook his head.

He had come across many rulers of Hell such as Satan, Belphegor, and Mammon since coming to Earth, but they were nothing compared to the Heavenly Demon.

He had been at the pinnacle of all those who practiced the demonic arts, and was like a god to them.

'No matter how strong this demon king is…'

There was no way he could compare to the Heavenly Demon.

Crimson Fiend had used a forbidden technique to travel to another dimension exactly because he was sure that he would never be able to become a ruler if he stayed in Huan.

'One day…'

His eyes began shining with madness.

He was following Satan's commands because he couldn't go beyond his limitations as a human at the moment, but he dreamed of killing them all and standing at the very top. For that dream, they needed to win this war at all costs.

[W-We have to run.]

"What?"

Crimson Fiend laughed in exasperation.

How strong was the demon king for Belphegor to react in such a way?

[I am going b—]

Clutch!!

Belphegor had turned around when, suddenly, a darkness spread and grabbed his shoulder.

Slam!

The darkness shoved Belphegor back into his chair.

A being wearing a red demon mask walked out of the flickering darkness shrouding him.

[Sit down, Belphegor.]

[Sa…tan…!]

Belphegor glared at the being wearing a red demon mask.

[What is going on?! The demon king is alive?! What nonsense is that?!] he screamed.

Satan put more strength into the hand gripping Belphegor's shoulder.

Rumble!!

The huge mountain shook.

[Kuh!]

Belphegor grunted in pain.

Satan's eyes gleamed with complexity, and he said, [I do not know either.]

[What…?]

[I do not know how the demon king is still alive,] he said in irritation.

The revival of the demon king…

They had not even calculated that variable into their plan after they had arrived on Earth and discovered the Demonic Origin. It was only natural, since the demon king had been torn to shreds by the dimensional wall.

One could safely pass the dimensional wall by creating a hole in the dimensional wall using the Hell Armaments, but Satan had ordered Amon to make it so that the demon king would collide head on with the 'providence of the universe' which managed the border between dimensions.

Even a god wouldn't have been able to survive that, but the demon king had managed to survive.

He hadn't died.

[…]

Silence fell.

[What are you planning to do now?] Belphegor asked in a low voice.

[We will have to fight,] Satan answered without hesitation.

BOOM.

Belphegor sprang up from his chair once again.

[Fight? Are you out of your mind, Satan?!]

[Do you have any other way?]

Satan glared at Belphegor with cold eyes.

There was no compromise with the demon king; they had learned that the hard way back in Hell during their thousand-year war.

The man was crazy, in every sense of the word.

[H-How about we let him in on our plan and—]

[You know that he thinks of us as nothing more than food. I am sure you know what happened to all seven of us princes of Hell.]

[But he never bares his teeth at his subordinates!]

[Are you suggesting that we become his subordinates?]

Satan narrowed his eyes. Becoming the demon king's subordinates was something that they couldn't bring themselves to do.

No matter how much they feared the demon king, they were still princes of Hell. The blood of a ruler had been flowing inside them since birth. They couldn't even fathom the idea of serving someone.

[Kuh…]

[Enough nonsense. We must kill him before the demon king restores his full power.]

[Full power?]

[I have investigated him.] Satan continued in a low voice, [Unlike us, it seems he had arrived on Earth only two years ago.]

[Two years…]

Belphegor's eyes shone sharply as if he knew what Satan was trying to say.

[He seems to have been raising his strength while concealing his identity among the humans.]

[Then that must mean…]

[Correct.] Satan nodded. [He lost his power when he collided with the dimensional wall, just like we had.]

[…]

Belphegor remained silent.

Crimson Fiend, who had been silently listening, joined the conversation.

"But angels will also be joining this war, are they not?"

[Raphael…]

The darkness surrounding Satan fluctuated.

Because of the demon king's manipulation, they could no longer avoid an all-out war against the angels. If things had gone according to their original plan, they would have faced the angels at least a few decades later.

[I have an idea.]

He thought of a way to face Raphael and kill the demon king at the same time. It would have been impossible before, but there was a possibility now.

Satan looked at the Demon Cultists, and demons lined up.

[That aside, where is Kalgia?]

"I do not know. He cannot be reached after he had gone somewhere to investigate the Demon of Prophecy."

[Again?] Satan shook his head. [Well… This should be enough for now.]

Kalgia wouldn't be of much help in a war anyway. He specialized in summoning and black magic; he was similar to Amon.

[Satan, will you really be able to kill the demon king?]

[Yes, if things go according to plan,] Satan said firmly. [And if we manage to kill him…]

[…]

Belphegor remained silent.

He gulped.

It wasn't hard to imagine what Satan wanted to say.

[We will be able to acquire… the Demonic Sea.]

[Exactly.]

Belphegor's eyes filled with greed.

It was a reward so sweet that it could erase his indolence.

[Alright, tell me the plan.]

Belphegor took a seat again. His greed-filled eyes gleamed.

'Two years…'

It was a short amount of time, even for a mortal human.

'We can do it.'

He thought that it was more than possible.

'It has only been two years.'

A very short amount of time.

'Even if it is that monster…'

There was no way he had fully restored his power in just two years.