The Cost of Symbiosis
“The researchers never questioned whether I could get pregnant?”
“Information regarding Succubus reproduction is classified at the highest level. Eight years ago, a researcher tried to access those files, so we had to replace a great many of them. Everything the current staff knows about Succubi is heavily restricted.”
Faust stared at my lower abdomen with visible shock. “How is ovulation even possible? The only differences between you and QA are that you’re a younger adult and that you carry an Abaddon symbiote.”
“Probably thanks to the Abaddon. Kyubey can regulate her own fertility too. And please don’t call it an infection—call it symbiosis.”
“That makes sense. I’m the one controlling it, after all.”
“We won’t know for certain until you actually conceive and give birth, but it seems we may have discovered an entirely new method of reproduction.”
Faust rubbed my belly with his hand, muttering about research protocols with sharp, calculating eyes. “If I use the high-quality sperm samples we’ve stored for research and perform artificial insemination…”
“Grandpa, Kyubey already has a husband. You can’t just impregnate her with some stranger’s seed. That’s too much.”
“A husband? When did you manage to find one of those? …Hmph. In that case, it’s a shame, but there’s nothing to be done.”
Despite how eager he had been moments before, Faust backed off cleanly. That wasn’t like him at all.
“You’re giving up that easily?”
“Choosing a mate for the purpose of reproduction is an extremely important matter for humans. If she’s already engaging in reproductive activity of her own volition, there’s no need to force the issue. What a commendable child.”
“Your values really are strange, Grandpa.”
“Hohoho. To think an Abaddon child would call my values strange. How refreshing.”
Once the weapon inspection was complete, I shifted back into human form. From a third party’s perspective, the sight of the two of us standing there naked and conversing probably looked rather compromising.
“I’m also deeply interested in Abaddon ecology. Would you be willing to provide a sample?”
“Hah. You want to use our child as an experimental subject? Absolutely not.”
“I believe it is necessary for the sake of human-Abaddon symbiosis.”
“Symbiosis that benefits humans, you mean!”
“Naturally. Abaddon cannot survive without a host. True equality was never part of the equation. What do you think, Kyubey?”
“Me?”
The conversation had suddenly turned to me while I was busy untangling my hair from my horns.
“As someone who was once host to that audacious Abaddon, tell us your thoughts on symbiosis with it.”
I didn’t understand why Faust was asking me this when he already knew I served Maria as my master. Under Maria’s tense gaze and Faust’s calm one, I answered.
“In simple terms, it’s a relationship where Abaddon holds the initiative. If it wanted to, it could control every aspect of the host. From a human perspective, it’s definitely a dangerous organism.”
“Kyubey!” Maria called out and rushed toward me, but I raised a hand to stop her and continued.
“However, an Abaddon that chooses symbiosis rather than parasitism acts for the sake of its host. It prioritizes the safety of both itself and the host, and does many things to ensure the host’s happiness.”
In the end, Maria had taken over my body, but that had been the result of a choice made to protect both the original host—me—and herself. Senior Stella falling asleep, Isabel swimming through dreams—everything had been for the host’s happiness.
“Having experienced symbiosis firsthand, I believe an Abaddon that chooses symbiosis makes a good partner.”
“Very well. Then there will be no problem so long as the symbiote Abaddon itself agrees to participate in the research.”
“Huh? It works like that?”
“Kyubey, you idiot!”
Maria smacked my back in anger while Faust looked thoroughly satisfied.
“If you say that, then any Abaddon that wants symbiosis with humans will have no grounds to refuse experiments conducted ‘for the host’s benefit’! You fool!”
“Ah.”
“Who knows what Grandpa might do to his own kind, and you just blurt that out without thinking!”
“Ehh, but if it’s Faust, he wouldn’t do anything that would harm us.”
“Tch. Look at this brainwashed girl talking.”
“Ow ow ow, that hurts.”
I clutched at the hair Maria was yanking while looking at Faust. He watched our bickering with fond amusement before uncrossing his arms.
“Kyubey is correct. I hold Abaddon’s potential in high regard. If it can freely control the host’s body, then it can also control any negative effects on the human body. The key question is how far an Abaddon is willing to endure and sacrifice for its host. That is all I wish to determine.”
“Hmph. Easy for you to say. If you decide they’re unsuitable by your standards, you’ll just kill them, won’t you?”
“Hohoho. Maria, you really are clever. Indeed, with a host like Kyubey, one might feel insecure enough to seize control of the body.”
“You annoying old man.”
Despite their constant bickering, the two of them actually got along quite well. Maybe that was just how intelligent people connected. Faust teased Maria, yet supported her learning without reservation. Maria called him “Grandpa” and grumbled, but she carried out his requests diligently.
Maria, still visibly displeased, eventually left the bathroom first, leaving Faust and me alone.
“Hoh. What a cute child.”
“Master is definitely cute.”
“Though her mouth is rather foul. By the way, Kyubey.”
“Yes.”
At Faust’s gesture, I approached, knelt, and lowered my head. He looked flustered.
“There’s no need to kneel.”
“Ah, it was just habit.”
Living with Master had become so natural that whenever I was alone with a man of higher status, I instinctively knelt and bowed. It wasn’t just me—most Queens who had been trained as slaves by their masters shared this habit.
“Sit comfortably.”
“I’m fine. This is more comfortable for me.”
“If that’s what you prefer, then so be it. Hmm.”
Faust brought over a bathroom chair and sat down, studying me carefully before continuing.
“Do you know what I asked QA to do?”
“You mean Master’s education?”
“So you knew. It was meant to control Maria, but I heard you stopped it.”
“Yes. I didn’t want Master to be controlled by anyone else.”
“Hohoho. You say that even after brainwashing your own master?”
“It was only a measure to protect her.”
“And yet you make full use of it. As expected of a Succubus.”
Faust nodded approvingly. I didn’t understand what I had done well, so I asked.
“What did I do well?”
“You’ve completely taken Maria under your control. It’s QA’s role, but since you’re also a Succubus, it should be fine.”
“I don’t see how that’s a good thing. I only did it for Master’s sake.”
“Hohoho. You know Succubi are a persecuted race, don’t you?”
“Yes. I know the Sun God Cult was responsible for driving them to near-extinction.”
“In such circumstances, having a Succubus control the one who will rule Eden is a way to secure a safe place.”
I thought Master would never abandon me, so his concern seemed excessive, but I simply listened quietly.
“You and Maria were born and raised in Eden, so you may not understand, but humans are inherently dangerous beings. They will readily use and discard even their own kind for personal gain—a cruel species. And you are a Succubus, a persecuted other-race. You must always live with caution toward humans. Do you understand?”
“Mmm, I understand.”
The foreign men I’d met while working as a bartender in Eden hadn’t seemed particularly bad, but I decided to accept Faust’s goodwill in worrying about us mother and daughter.
Still, curiosity got the better of me. “Are foreign humans really that dangerous?”
“Hmm. Let me give you a simple example. Do you know that beyond the western sea of this continent lies another continent?”
“Yes, the Western Continent.”
“There exists a nation that treats women as slaves at the national level. The lives of women used as sex slaves there are said to be unimaginably cruel. While remnants of treating fellow humans as slaves remain on this continent as well, they were merely labor slaves working in fields or mines. Enslaving an entire gender so thoroughly is beyond imagination.”
Oh. That was Master’s country. He didn’t seem to know about the recent changes.
“You mean Daviwana? Recently they passed laws improving slave treatment. Violence and verbal abuse toward slaves have been restricted, and they’re even providing education.”
“How do you know about that?”
“My husband is the branch manager dispatched from Daviwana to Eden.”
“That violent, cruel black man is your husband? Tell me the details.”
Since it was Faust, I figured it was fine to talk about Master and explained everything from our first meeting onward. His expression grew increasingly strange as I spoke.
“So when he asked me to bear his child, I asked if it was a proposal, and we decided to get married.”
“Hah. So those black men were causing such trouble in Eden. And what will you do if a man says he likes you and you become a slave so readily?”
“He’s exactly my type.”
“Maria taught you wrong. Obedience is fine, but a child who submits to anyone is problematic.”
“I don’t submit to just anyone. I have my own standards.”
“Strong males, you mean? Hmm. Now that I think about it, I can’t imagine there being any male stronger than you. Perhaps I needn’t worry after all.”
That was true. Master had only been slightly stronger than me at first; now he couldn’t even compare. The only males stronger than me now were probably monsters.
While I was thinking this, Faust pointed to the space in front of his seat.
“Come closer.”
“Yes.”
I crawled on my knees into the space between his legs. As someone who personally used various products made with vital energy crystals, his body—younger than his age—held far more vital energy than the other researchers. I caressed his half-erect member with a hand infused with vital energy.
“Oh my. It’s been rather lifeless since earlier.”
“Your mother tormented me a bit before I came here.”
“Then I’ll be gentle with you.”
Instead of absorbing vital energy, I infused it, gently channeling energy into him. The listless member that had only been half-erect gradually responded to my touch and began to harden fully. Faust rested a hand on my head as I knelt and pleasured him, his expression pleased.
“Hoo. QA has such a strong childish side that she’s greedy for vital energy. She always drains men until they’re on the verge of collapse. Compared to her, you certainly know what men want.”
“Hehe. I’m not a former angel and active slave for nothing, you know? I’m confident when it comes to serving men.”
I harmonized my vital energy with Faust’s and gradually accumulated it in his testicles. It was an application of the efficient absorption method Mother had taught me, but reversed to transfer my vital energy to a male. I had developed the technique while pondering ways to enjoy longer sessions with Master.
The more vital energy I expended, the more accumulated in his testicles, making his member even harder. Veins stood out as it radiated heat, twitching and leaking precum.
“There. Full recovery complete! How do you feel?”
“It’s like a vitality tonic. Where did you learn this technique?”
“I made it so I could enjoy longer time with Master.”
“Hohoho. A Succubus who doesn’t consume vital energy but expends it to please men. How admirable.”
Though the fully charged member twitched before my eyes, I felt no arousal without Master’s pheromones. Perhaps Master’s pheromones were an even stronger restraint than the collar.
Faust frowned slightly, as if uncomfortable.
“The erection is so strong it’s rather painful.”
“Ah, I see. Just a moment.”
I placed my hand on his testicles and forcibly calmed the vigorously active vital energy. As the energy settled, the force in his member diminished and the erection subsided. I placed a locking mechanism on the large amount of vital energy gathered in his testicles so it wouldn’t become active again, and set it so Mother could release it.
“There. All done.”
“Sexual desire remains, yet no erection occurs. You know many fascinating techniques.”
“It’s an application of Yin Brand vital energy manipulation. Unless the lock is released, the energy will only accumulate without causing an erection.”
“Then how does one achieve an erection?”
“Huhu. If you show it to Mother, she should be able to release it.”
“My, my. So you did this with your mother in mind. What a good daughter.”
“Because Faust is Mother’s man.”
I had no intention of mixing bodies with Faust, who was especially favored by Mother. No matter how much a Succubus craved male vital energy, I believed a mother and daughter should maintain certain boundaries.
Faust, who had been stroking my head, spoke in a low voice.
“Are you confident you can kill Eden’s god?”
“I know how strong I am. I’m confident.”
“I’m not asking about strength. I’m asking whether you can kill a person with your own hands.”
Those words momentarily left me speechless. Even though I had spoken of killing Eden’s god, I had never deeply considered the act of murder itself.
Right. Because I’d said “kill a god,” it hadn’t felt real, but in the end, it meant killing a person. Could I kill someone? I pondered briefly, but the answer was “I don’t know.”
“I’m not sure. Until now, I never thought of it as murder.”
“I see. You never received education about murder, yet you were so nonchalant that I found it strange. So you hadn’t even recognized it as such. Still, the fact that you’re uncertain suggests you don’t have a strong aversion to killing. If you want smoother mission execution, I’ll provide appropriate training.”
“Will training help with killing the god?”
“At the very least, you won’t hesitate and fail.”
Faust’s firm words made me lean toward receiving the training. It was an important mission that would determine Eden’s success or failure—I didn’t want to leave even the slightest element of uncertainty.
“Then I’ll take it.”
“Good. Then let’s head out now.”
Faust smiled brightly, looking satisfied, and we left the bathroom together, heading toward the research lab. Following him, I found myself walking down a corridor I’d never seen before. Ah, Master would be waiting.
“Can I go tell Master first?”
“It won’t take long, so don’t worry.”
“Okay.”
After walking a bit further, we arrived at yet another unfamiliar lab. Complicated machinery lined the walls, and various specimens were displayed, creating a somewhat gory atmosphere. It reminded me a little of Isabel’s lab.
“First time in my lab?”
“Ah, so this is Faust’s lab.”
“I’ll have things prepared before QA arrives. Take off your clothes and sit over there.”
“Yes.”
I did as instructed, removing my clothes and sitting in the chair positioned between the massive machines. The cold metal of the chair transferred through my skin, making me shiver. When Faust operated the machinery, metal bands secured my wrists, ankles, neck, and waist to the chair.
“Eek. It’s cold. And sturdy.”
“This should be more than enough to withstand your strength.”
Something was placed over my head—which couldn’t move due to the neck restraint—and fixed in place. While I waited, moving only my eyes, a sudden pain pierced my skull and all bodily sensation vanished.
Huh. My eyes won’t move either.
“A brain-penetrating control device. It’s an old-fashioned method for someone who’s already received implant surgery, but the effect is certain. Your eyes will feel cold, so I’ll close them for you.”
My field of view, fixed toward the right, darkened as my eyelids closed. This felt a bit different, but it was similar to being controlled through the implant.
“Kyubey, you’re too kind. Kindness is good, but to survive in this harsh world, you need at least a ruthless heart capable of decisively dealing with enemies.”
I heard clattering sounds, as if he was preparing something. Then came the distinctive sound of the lab door opening, followed by approaching footsteps.
“Darling~ You called for me~?”
“I’m going to educate Kyubey.”
“Aah~ Daughter~ It’s been a while since our last education session~”
Mother’s delighted expression flickered before my eyes. Even when I was still a young Succubus receiving education, Mother had always been extremely pleased.
Whoa, my head suddenly feels fuzzy. This is similar to when I received education before.
“I’ll open your eyes now, so you can begin.”
“Yes~ Daughter~ Don’t resist and just accept Mommy’s charm~”
Ugh, I’m getting dizzy. Mother’s voice echoed and reverberated in my head.
Soon my eyes opened and met Mother’s charming gaze. Ah, this sensation—it’s been a while.
“Yes~ Accept it deeply like that~ Deeper~”
As Mother’s charm intensified, my consciousness grew distant. Haa, it feels good.
“Maintain the charm. Beginning now.”
Along with Faust’s faintly heard voice, my consciousness faded into darkness.