"Haah!"
"Kikiii!"
I thrust out the [Absolute Spear], which was imbued with spiritual power, at the small creature in front of me.
The enemy I am dealing with now looked like the demon I first encountered, but it was even shorter and looked like a goblin from another world, and it was called an imp.
I was currently training under Kuuya-san's guidance on how to handle spiritual power, and as part of that training, the imp was specially created by Kuuya-san using his own spiritual power.
The creature, pierced through the torso by my attack, vanished like dust.
Kuuya-san watched the scene and nodded.
"Umu. You've mastered the use of spiritual power quite well. You've passed your first goal of applying the power to an object."
"Phew… Thank you very much."
I let out a sigh of relief when I managed to get a pass from Kuya-san.
Then, Ouma-san, who had been watching my training, had a curious look on his face.
"Hmm… the more I look at it, the stranger the power is… I've never seen anything like it before. Moreover, unlike 'Evil,' it is not a negative power, but I didn't know a power with such a dense sense of death existed…"
"So even Ouma-san is not familiar with this power… By the way, is it possible to acquire this spiritual power after birth?"
When I asked Kuuya-san what was suddenly on my mind, he shook his head.
"It would be difficult. As I have explained, spiritual power… in other words, the power of spirits, is a power that should be avoided by the living. The degree of defilement by death is much stronger. Therefore, it is necessary to have a body that can originally store spiritual power. If you are born with a small amount of spiritual power, it is possible to increase it."
"Well… one thing I was wondering is that if you don't have the power originally, it is difficult to acquire it later, isn't it? Then why did I… or Kuuya-san, for that matter, have the spiritual power in our bodies?"
"It's simple. It means that our ancestors had demons' blood running through their veins."
"Huh?"
I was not expecting that, and my eyes widened.
"I explained that demons are souls that have somehow escaped from the underworld and have been transformed… In the days even before I was born, the boundary between the underworld and this world was less defined than it is now. Therefore, demons sometimes traverse into this world."
"Such a time was…"
"At that time, some people were forcibly attacked by demons and became pregnant with demon children, while others genuinely fell in love with demons and had children born with both human and demon blood. Such was the case with our ancestors, and as a result, the blood of demons flowed through the Tenjou family."
"I-I see."
"So, it is almost impossible for a living person to acquire the power of a demon. There is nothing to do but to give up."
"Mmm…"
"Woof!"
Ouma-san seemed to be interested in the spiritual power, and he was not so amused when he heard that he couldn't acquire it. In the same way, Night had hoped to acquire spiritual power, but he seems disappointed that this possibility has vanished.
"It is impossible for you guys to acquire the spiritual power, but there is a way for Yuuya to raise his own spiritual power."
"Eh?"
"Well, it's not a method I recommend, but… it's a method of forcing another person's spiritual power to dwell in your body."
"Dwell?"
"Yes. It would be similar to when you took… that strange power inside of you."
"…This guy, is he aware of my existence…?"
Kuro was surprised by Kuuya-san's words, as he didn't expect that he would in this discussion.
It was the same for me. I had not explained Kuro to Kuuya-san, but he easily saw it right through.
"Don't be so surprised, okay? I can detect the presence of power just as you can. I can also tell you how you obtained that power. If Yuuya can sharpen your sense of power, you will be able to do it."
"I-I see."
"…I know this is a bit off-topic, but it seems that Yuuya has taken on this power and put it in your body, right? In the same way, you can increase your own power by absorbing the power of another."
"Can you do that to any demon?"
"Well, you can, but as I said at the beginning, I don't recommend it. What's more, you can't just absorb the power of one demon after another; in other words, it is the same as receiving the stain of death into yourself. Moreover, most of the demons that you have encountered are those that have been tainted with evil, even in the underworld, and even their souls are tainted with malice. You and I have demon blood in our veins, so our bodies are accustomed to the power of demons, but if one suddenly accepts such power, it will have an adverse effect on them as well."
"I-I see…"
"The safest way to increase your power is to use up all the power stored in your body. Even if a person who has spiritual power in their body uses up that power, they will recover little by little. And with each recovery, the amount of spiritual power stored in the body increases, albeit only slightly. Yuuya and I have a lot of power, so it is difficult for us to consume it, but this is the safest and most reliable way to do so. Everything is best done steadily."
It's true; I've seen firsthand how sudden gains of power result only to be swept away… While I was getting a lecture from Kuuya-san on the subject of spiritual power, I suddenly realized something.
"Come to think of it, where are Lexia-san and the others…?"
"Hmm? They went shopping."
Lexia-san and the others didn't just come to Earth to study. By looking around the Earth, I guess there are some things that can benefit the Kingdom of Arcelia.
"I wondered what would happen to them at first, but I'm glad to see that they seem to be adjusting well to Earth."
Yuti also made some friends a short time after arriving on Earth.
Lexia-san and Luna also seem to be basically enjoying themselves, even if they are a bit bewildered by the cultural differences.
After finishing my training, I returned to my home on Earth and was about to prepare dinner for Lexia and Luna…
"!?"
Suddenly, a cold shock ran down my spine.
It was similar to the feeling I had when I first confronted the demon… but it was so dense and deadly that it made the demon of that time seem almost adorable.
I looked around in a panic, and a mysterious black vortex appeared in front of me, and a muscular arm stretched out from within.
And following the arm, it appeared, looking at first glance like a Bloody Ogre from another world.
Moreover, not only one but several of them appeared in succession.
Although I said they looked like Bloody Ogre, their skin color was very colorful, yellow and light blue, and upon closer inspection, their eyes had a light of reason in them that demons do not have.
What can I say…? The word "Oni" seems to fit them well.
Nevertheless, one of the oni notices me while I am still alarmed by the presence that suddenly appears, sprinkled with a hint of death.
"You must be Yuuya Tenjou, right?"
"Eh? H-how did you know about me…?"
I was surprised that he spoke the human language, clearly different from Bloody Ogre, who is, after all, a monster, but I was even more surprised by the content of his speech.
The oni continued indifferently to me.
"Reimei-sama wants to see you. Follow me."
"Reimei…?"
I asked back unintentionally, and at that moment.
The presence of the oni suddenly changed to something disturbing.
"You… how dare you call out to Reimei-sama with such disrespect!"
"Eh? I-I didn't mean to call…!"
"…It looks like we need to give you an education before we send you to Reimei-sama."
The oni approached me, clicking their arms.
The next moment, a yellow demon suddenly struck me.
"Oraa!"
"Kuh!"
I quickly jumped back and deployed my "Magic Armor" and also activated my "Holy Evil Creation."
In any case, in order to get them to calm down and listen to me, I have to fight back first…!
"Haaah!"
Since we were inside the house, I hit the oni without exerting too much force, but it didn't look as if he had sustained any damage. Is this with… spiritual power?
"It's no use. People like you can't even hurt us. You should be beaten down quietly."
"Hmph!"
"Gaahh!"
"What?"
I immediately realized that I needed to use my spiritual power, so I spread my spiritual power throughout my body and once again kicked at the oni's torso.
It seemed that the opponent thought that I could not handle the spiritual power and did not even defend himself properly, so my kick connected with him, and the yellow oni went down on his knees, holding his stomach.
Seeing this, the other oni were alarmed and, at the same time, enraged.
"You… know your place, human…!"
"Kuh!"
The other two were in a rage as well as alarmed.
"Take this!"
"Oh, no!"
Having a punch thrown into my bosom in an instant, I can't avoid the oni's attack… the moment I'm ready to take the attack…
"──What are you doing?"
"Wha?"
"Ah, Ikkaku-sama!"
"…Huh. It seems that the information was not well received."
Suddenly, someone quietly caught the oni's fist that was unleashed on me.
He was a blue-skinned oni, but he was far more rational than the other oni, and above all, I was horrified by the calmness of the spiritual power overflowing from his body.
The reason for this is that the oni I had been fighting up to this point had attacked me while releasing, rather than restraining, their spiritual power.
In contrast, the oni called Ikkaku's spiritual power was so serene that it did not appear strong at first glance.
However, the subtle overflow of his spiritual power was frighteningly dense.
Surprised by the sudden intruder, I heard Kuuya-san's voice from behind me.
"Phew… you suddenly started fighting, so I hurried to protect this house with my spiritual power… but I'm tired."
"Eh? Oh… S-sorry!"
It seems that Kuuya-san tried to break into the fight against the oni, but rather than that, he divided his efforts so that this house would not be destroyed.
"It's okay; it's okay. In fact, it would have been better if it had been stopped earlier. I didn't expect the oni, messengers of Reimei-sama, to come. It seems that the underworld is finally getting quite noisy."
"…You… I see, you are a thought body. It seems that you had great sorcery skills in your life to be able to leave such a beautiful thought body.
The blue oni was surprised at Kuuya-san's appearance, but Kuuya-san shook his head.
"Please stop. I'm not that big of a deal. More importantly, are you looking for Yuuya over there?"
"Oh, yes, I was… I am one of Reimei-sama's messengers. I am sure you have heard from these onis, but our lord, Reimei-sama, has summoned you. So I sent these oni to pick you up… It seems that there has been some rough treatment on our part. I am very sorry."
Ikkaku-san bowed his head without hesitation as he said this.
"Oh, please raise your head! I'm not particularly hurt, and I'm fine! More importantly, why is it that I am being called by the one called Reimei-sama…?"
I was surprised to be suddenly attacked by these onis, but that was still fine.
More than that, I couldn't understand why Reimei-sama, the supposed master of these onis, was calling me all of a sudden.
"Regarding that, I would like you to hear from Reimei-sama herself… I would like for you to come to the underworld and talk with her."
"Eeehhh? U-underworld?"
An underworld is a place where the dead go, right? I'm invited to a place like that, and I'm still alive… Is that okay? I'm not going to die from this, am I…?
Perhaps my concern was conveyed, Ikkaku-san continued.
"You must be worried if you are suddenly told to go to the underworld. However, if it is Yuuya-sama, you seem to have spiritual power in your body, and more than anything else, you are invited by Reimei-sama. There is no need to worry about that sort of thing."
"I-I see."
"But unfortunately, only Yuuya-sama has been invited, and I can't take everyone over there with us."
"Eh?"
"Woof?"
"Buhi?"
"Pii!"
"…What did you say?"
Even if we were to head to the underworld, I had assumed that Night and the others would be able to go with us, and my eyes widened involuntarily.
"I know you may disagree, but it's something that can't be helped. As you all know, the underworld is the land of the dead. The land of the dead is permeated with the stain of death. In order to spend time there, you must have spiritual power."
"If that's the reason… then what about Kuuya-san? I think he is much more skilled in the use of spiritual powers than I am…"
I introduced him as such, and Kuuya-san shook his head.
"No, it is impossible. Even though I have spiritual power, I am originally just a thought that I left behind in that scroll before I died. Therefore, my true body exists in the underworld. So, I can't follow you now."
"No way…"
"Don't worry. I can still exchange memories with my body, and my body in the underworld will know about Yuuya. I'm sure my body will serve you well when you go to the underworld."
"I understand that you are confused by the suddenness of the situation. But I really want Yuuya-sama to come to the underworld. Please, can you help us?"
After saying this, Ikkaku-san bowed his head again.
Then, as if to help Ikkaku-san, Kuuya-san also asked me for help.
"Sorry, Yuuya. If you can, will you lend them a hand? These oni serve the lord of the underworld, Reimei-sama. This one, in particular, can be called the right hand of Reimei-sama. The fact that they came directly to this place must mean that something terrible is happening in the underworld. That's why…"
To be honest, I am still puzzled.
Nevertheless, I cannot just sit back and be silent after being bowed down to.
"I understand. I don't know what I can do, but… please take me to that Reimei-sama."
"Thank you very much!"
Ikkaku-san snapped his fingers as he said this.
At that moment, a black vortex appeared in front of him, same as the one the oni had first crawled out of.
"This way, then."
"…So I'm off to the underworld. I don't know what will happen, but please keep watch at home."
"Woof! Woof, woof!"
"Buhi!"
"Pii!"
"…Well, if you're the only one who can go, then so be it. I'll take care of the house for a while."
Night and the others raised their hands as if to say, "Leave it to me," and Ouma-san turned away and said so.
"I'm sorry, Yuuya. Please take care of it."
"Yes!"
When Kuuya-san said this to me for the last time, I stepped into the vortex.