#040 Secret Art
#040 Secret Art
Belphegor—I, the Demon King, excel in a truly vast range of fields.
Magic, swordsmanship, spearmanship, archery, even the arts of the bedchamber—I boast outstanding ability in every conceivable area.
'Because it's me.'
It wasn't for nothing that I ground through six Holy Sword Heroes and countless Hero Parties.
'Because I put in that much effooooort.'
The way I defeated countless heroes was by fighting enemies, by secretly slipping into Hero Parties and learning from them, by seizing and stealing enemy techniques and learning them, and by exploiting enemy weaknesses.
'Only I could have done it.'
This isn't self-praise; I learned from countless people, and learned again, and gained that many techniques.
Among the Demonfolk, there is likely no one who possesses more techniques than I do.
Truly, a paragon of versatility.
But fundamentally, my ability—the one I can pride myself on using best, using most easily, and using more superbly than anyone else—is Possession.
'I can possess with just the mana equivalent to a Mana Stone from a single slime.'
Dwelling within something.
Whether human, corpse, or any existence at all, I can breathe my spirit into it and dwell within that existence.
That is my Authority, my Essence, my Power.
Seizing the body of a colossal Black Demon Dragon and dwelling within it, and stealing the body of an insolent black mage when I was first summoned to the Human Realm—all of it was the power of Possession I possess.
There are limits.
There are restrictions.
Since I can only dwell in one body at a time, my original body loses consciousness and is abandoned.
And the more alive a being is, the more it possesses a clear mind, the harder it is to dwell within that body.
'Since it's a method of a spirit dwelling in a body, if another soul already dwells there, it's hard to seize the body.'
A corpse with no mind or soul at all is naturally easy to possess, but it is difficult to possess the body of a being whose mind clearly remains.
So I collected only corpses.
I used only bodies I could dwell in at any time, and the reason I use this body is also, in the end, because I possessed a corpse.
'But possessing a being that isn't a corpse?'
In that case, things become troublesome in many ways.
Entering a body inhabited by a soul means seizing the body through a 1-on-1 death match in the Mental World.
If the other party surrendered their body to me with pure intent, that would be one thing, but if not, I do not recklessly try to steal the body of a living being.
'But if it's a body the other party has granted me permission to use, that's a different story.'
Unless it was someone who truly believed in and trusted me enough to let me use their body.
So I conducted an experiment.
Whether Lucius truly believed in and followed me.
'Will Lucius hand over his body to me willingly?'
If he hands it over, I can also show Lucius another way to use the Holy Sword.
'A Holy Sword isn't something you can only use by drawing the sword and swinging it.'
I thought this was a good opportunity to show him my power as well, and to show others how much stronger I become when I dwell in Lucius's body and link with him.
That even without revealing the Holy Sword directly, I can produce this much power.
To be precise, it is using the Holy Sword's power, but there is a way to produce power equal to the Holy Sword without openly revealing the Wind Holy Sword.
Body enhancement.
A method of using the Holy Sword's power solely to enhance the body.
Since I'd have to teach Lucius someday, showing him through indirect experience this time wouldn't be bad either.
So I stepped directly into Lucius's body—into his Mental World.
Taking the risk.
"Master...?"
This place was a pure white world.
There, Lucius came to face me head-on.
"Yes, it's me."
The Lucius before me was a Spirit Body.
His entire body was an opaque ether form, his physical shape filled only with outlines, a typical soul form with no vital regions present.
The same was true of me.
"M-my body...?! No, before that, my clothes...?!"
"Why?"
I examined my own state.
'There doesn't seem to be a problem.'
I was slightly anxious that my original appearance might be revealed, but fortunately, I was able to show the appearance of the Crimson Mage even in the Mental World.
'It might be a bit too stimulating for Lucius, though.'
It was very different from my appearance in reality.
If my appearance in reality was nothing more than a little girl, then my current appearance imitated the actual Crimson Mage.
If my real appearance was a girl, then my current appearance was like a suspiciously ageless, youthful, beautiful mother with a daughter.
'Even I can see she's certainly remarkable.'
Not a girl, but the form of a fully matured woman.
It was a form so beautiful that even I could feel my mouth water.
'Perfect disguise.'
Because it was a Spirit Body, the vital regions weren't visible—only the shape of the body was—but even that silhouette alone was enough to set a man's heart ablaze.
The body that originally had a bit of volume had grown to the point that Rosemas could only dare call it "nothing."
The Crimson Mage.
She is 8th Circle.
A being who carries around two mana reservoirs larger than men's heads.
'She was good.'
I remembered the time I defeated her.
Ah, the Crimson Mage was truly good.
Beyond words.
'She was truly the best woman among humans.'
That was why, when choosing a red-haired form, I'd picked the Crimson Mage out of countless red-haired heroes. It hadn't been an arbitrary choice.
"Why are you looking at me like that, Lucius?"
"I-it's nothing. It's just... awkward."
"That's understandable. Hm."
No matter how little interest Lucius tried to take in women, there was no way he could avert his gaze from a body like this.
"Master, what suddenly happened? That appearance is...?"
"The Crimson Mage. You could call it my original appearance."
"Then your body...?"
"Ah. Outside? Should I call it a temporary body, or a similar body? Well, it's different from my body five hundred years ago, right? I lost my original body in the battle with the Demon King. This is... hm, a spare body?"
I did not lie.
"If you seal a body wounded in battle, the wounds would rot and fester, wouldn't they? So I changed bodies. To a body suited for sealing. And as I kept at it, I made it more efficient with less mana consumption, and it ended up smaller."
That was enough of a cover story.
If I had seen the girl's soul, I could have changed into the body owner's body, but unfortunately, by the time I possessed the girl, she was already dead.
"Lucius. That's not what matters right now. The enemy is using automatons, and without the Holy Sword's power, we are in a desperate moment."
"...Yes. Then the Holy Sword Release..."
"I'm going to teach you another way to use the Holy Sword."
"...Pardon?"
"A Holy Sword isn't something you can only use by drawing it as a sword. The Holy Sword's power is something you can use even in the ring state you have right now."
"......."
Lucius seemed unable to believe it.
Because until now, in all his training, he had never been able to use the Holy Sword's power without drawing the Holy Sword.
"So I'm saying I will personally dwell in your body and use it. While I move your body, you will see it as if observing yourself from behind."
As if a Summoned Beast were watching its summoner from behind.
"You just have to watch and learn. Another power of the Holy Sword that you can use."
"W-won't it be awkward? It's a man's body."
"What? Your worry is excessive. Lucius. You don't need to worry about that. What you should be worried about is..."
I pointed at my own body.
"That I'll handle your body so well, you'll feel a sense of loss for nothing."
"......."
Lucius bristled.
I extended my hand to him again.
"I'll show you. I'll be a little rough with your body, but I'll teach you everything I can teach."
I had to take his hand and earn his trust, both physically and mentally.
Once I receive permission, from then on, as long as trust is not broken, I can use Lucius's body without complicated procedures.
"For now, watch. And someday, when the time comes, when your skill improves, the day will come when we fight together."
Probably, at least a thousand years from now.
"Lucius. Are you ready to properly put your body to work?"
"...Is there any harm to you, Master?"
"Me?"
"While using my body, is there any harm to you..."
"Well, it would be a lie to say there is none."
Since it does use mana.
"But that's not the important issue, Lucius."
"...Understood. I will learn as hard as I can."
"Good attitude. Then..."
I approached Lucius and grabbed his face with my hands.
"I'll be borrowing your body."
SWISH.
The world darkened for a moment, and in my eyes appeared a flustered Rosemas and "my body," which had closed its eyes and collapsed unconscious.
"Wh-what...?"
"Swift."
I raised the iron sword at an angle.
I bent my knees slightly and leaned my upper body forward.
In a posture as if about to leap forward at any moment, I released the Holy Sword's power, manifested through the ring, outside my body.
"It's useless! Begin volley fire!"
Shax gave the order to fire.
At the same time, the automatons' muzzles all aimed at me—at Lucius's body.
Finger bones, each and every joint, were Magic Bullets that would pierce flesh.
Attacks that would send me to the grave if they hit.
But preparations were already complete.
I released the Wind Holy Sword's power and ran in the direction the wind led... and that was it!
"Whirling Wind."
WHOOOOOOOSH!!
The moment I twisted the soles of my feet slightly, wind began to surge from my entire body.
RATATATAT.
The wind became a barrier and shot down every bone bullet.
The severed finger bones and bone bullets scattered as bone dust.
"Secret Art."
It held no particular meaning, but I recited a technique used by a hero who came to mind, roughly.
'Showing off in someone else's body.'
"Gale Thunderclap (疾風迅雷)."
I kicked off the ground and ran.
I stepped on empty air and ran.
At a speed too fast to see, I moved like light and cut down automatons with the sword.
I cut down one automaton, immediately dashed toward another on the opposite wall and cut it down, pushed off the wall, then leaped forward again to cut down an automaton on the opposite wall.
I ran, cut, ran, cut.
It was simple repetition, but if that speed could cut down dozens of automatons in barely three seconds—
Then it became a divine art.
"Shax."
I landed again, as if guarding my body.
And pointed the sword at Shax.
"Now, only you remain."
KABOOOOM!!
The automatons exploded all at once.