This is a fantasy world.
A world where tentacle monsters exist, where goblins gang-rape humans and, once they grow tired of it, murder them, and where succubi suck the life essence out of humans.
I had even seen several instances where the training methods I came up with actually existed in reality.
But there were also cases where that wasn’t so.
Like the situation I was in now.
“Did you bring the slime?”
“Yes.”
The slime Lilith had brought was pink in color and slightly larger than a basketball.
“But what exactly are you planning to do with the slime...?”
“Give me the slime’s hand.”
I grabbed the slime’s hand and pulled it toward me.
The slime lacked sufficient intelligence and recognized me as a human, so it tried to resist by dissolving its mucus. However, after seeing the seal of the Vampire Legion carved into my face, it stopped trying to resist.
“From now on, you’re going to enter this woman’s stomach. Understand?”
“......What did you say?”
Casey asked.
“W-wait, what?”
“Maintain your body as much as possible. Consume any fluids that flow out from inside. Then burrow as far inward as you can and settle there until you’ve filled the inside completely. Can you do that?”
“Wait!! Wh-what are you doing?!”
Casey began to scream.
“You fucking madman!!”
“Go. Hurry.”
“N-no!!”
“Yes.”
When I pushed the slime forward, it clung to Casey’s ankle and began crawling upward as ordered.
“G-get off me! A-ahhh!!”
The loud clatter of chains rang out.
Casey twisted her entire body, trying to shake the slime off, but even against all that movement, the slime calmly climbed her leg like a snail.
“Good, good. Keep going up like that. You know where you’re supposed to enter, right? Don’t go into her asshole or urethra.”
I reached a finger downward and pried open the slit of her pussy from side to side.
“This way.”
Squish, squish.
The slime pushed its head into the succubus’s pussy.
“Nh—?!”
It must have been a sensation she had never experienced before.
Things other than a penis had probably entered her pussy often enough, but the creature known as a slime did not merely cover the entrance—it was pushing its head inside. That itself must have been a first.
Squish, squish.
The slime continued entering.
Climbing upward seemed somewhat difficult, but the slime followed the order it had been given, struggling with all its might to burrow into Casey.
Squish.
Casey clenched her thighs together, trying to crush the slime.
For a moment, the slime looked as though it might be flattened, its body stretching outward under the pressure like a rubber balloon.
“Secretary.”
“Yes.”
“Spread her legs apart. No. Can you make her dangle in midair instead?”
“As you command.”
Lilith snapped her fingers, and the magic formation binding Casey’s two legs with chains immediately rose into the air.
Clank.
In an instant, Casey was suspended with both her arms and legs spread toward the sky.
Lilith even made minute adjustments to spread Casey’s legs farther apart, leaving them opened wide in a V-shape.
“This should make it easier for it to go in.”
Squish.
The slime, which had barely been clinging to her thigh, instantly covered the mound of Casey’s pussy.
Perhaps enraged at having nearly been crushed between her thighs, the slime stubbornly forced its body into Casey’s pussy and burrowed inward.
“N-no, not inside...!”
“Yes.”
I grabbed the slime with both hands and pushed it in from behind.
The slime twisted its body awkwardly, resisting my hands, but the more it writhed, the farther inside it was forced.
Squeee.
The slime’s pitiful cry came from within.
As though it had already filled the inside of her vagina completely, it kept trying to bulge back out, as if it could go no farther.
“No, that won’t do.”
I supported the slime with one hand while repeatedly pressing down on Casey’s lower abdomen with the other.
“There’s still more room for you to enter. Search carefully.”
“Ah, ahh...!”
Casey lifted her head and looked at me, her eyes filled with horror.
“W-wait...! Please, wait, not there...!”
“Did you find it?”
The moment the slime burrowed deep inside and twisted its body—
“!!!!”
Casey threw her head back and twisted her body.
Her hands, raised toward the sky, tensed as though clutching at something, while her waist arched sharply upward.
Gluck, gluck, gluck.
The slime twisted its body.
Each time it burrowed deeper, the traces of slime outside continued to diminish, and the slime’s body gradually grew smaller.
The slime visible outside was shrinking.
Even in a narrow vessel, if there was somewhere it could force its body into, the slime could enter—as long as it did not burst.
A place where nothing was ever supposed to enter.
A place where, if anything did enter, it was supposed to be only a male’s semen.
“There. Can’t you feel your nest?”
The slime began burrowing farther into her womb.
“Nn, ngh, grrgh...!”
Casey twisted her body in distress.
Rather than suffering from pain, she was twisting in terror at the bizarre sensation of a liquid monster burrowing into her body.
“Secretary.”
“.......”
“Secretary?”
“Ah, yes.”
By then, Lilith had forgotten even to record anything in her notebook and was staring blankly at Casey.
“Can you turn the pain into pleasure now?”
“That...”
“Ah. Was it something that should have been cast before the slime entered?”
“......If the slime inside her womb interferes with the sex magic, then this may well be a new discovery in the field of sex magic.”
Lilith cast a spell upon Casey’s hand.
Whiiir.
Fortunately, a symbol resembling a vulva began to glow on Casey’s abdomen.
It was the sign that the sex magic had manifested—
“Euuungh!!”
Casey gushed.
Hot liquid streamed down both sides between the folds of her mound, which were still covered by the slime like underwear.
“Trainer. Succubus bodily fluids contain powerful aphrodisiac and intoxicating properties. Please be careful.”
“Ah, yes.”
I stepped aside at Lilith’s warning.
“Does it work on slimes too?”
“That...”
Brrr.
The slime trembled.
“It would be more accurate to say that it absorbs them.”
“I see.”
The slime had already been absorbing her fluids continuously as it burrowed into her vagina.
It might have been startled by the sudden gush, but those fluids also contained magic power.
Sluuuurp.
The slime began sucking up Casey’s juices in an instant.
It drank greedily, as though they were some kind of sweet beverage.
“Mmph, ngh...!”
Casey clenched her teeth and tried to suppress her moans.
Rather than looking like she was enduring it simply to avoid surrendering, her expression clearly showed that she felt her very existence might be destroyed if she failed to overcome this somehow.
Squish, squish.
The symbol on her abdomen swelled.
It felt as though the slime was burrowing through her vagina and crawling into her womb, indicating just how far inside it had reached.
“I don’t know much about demons, but I do know a few things about slimes.”
I moved to Casey’s side and pressed one thumb to each side of her lower abdomen.
“Slimes are creatures made of mana. They break down what they absorb into fluid inside their bodies, absorb the mana, and divide whatever remains into new slime.”
A slime’s reproduction was essentially a form of somatic cell division.
Her juices would certainly be mana that was easy enough to absorb, but there should be far more concentrated mana in this area, shouldn’t there? Hm?
“Aaaagh?!”
Press.
I pressed my thumbs into the area slightly above her lower abdomen.
I felt around for the places where the fallopian tubes extending from either side of the womb reached, pressing my thumb there and rubbing in circles to show the slime which direction to take.
“What do you think will happen if the slime reaches this far?”
“St-stop...! Stop it...!”
Even as tears streamed from Casey’s eyes and saliva dripped from her mouth, she pulled her head forward and begged.
“D-don’t let it go that far...!”
Casey knew with her own body what was happening inside her abdomen.
There was only one place the slime extending from both sides of the womb could reach.
“Why? Do you know what’s at the end of this path?”
“T-there...!”
“Don’t worry. Even if it hurts, all that will come out of it is pleasure anyway. Still, I suppose there’s no need for it to go all the way inside.”
I kneaded Casey’s lower abdomen from above, sending the slime signals through the vibrations.
“Settle inside the womb. Then feed on the fluids that flow out from there.”
A succubus would ovulate from the ovaries connected to the womb as well.
Since it was a place where a single life could be born at any time as long as it had a male’s seed, there would surely be a tremendous amount of mana gathered there too.
“And once you feel you’ve grown large enough...”
I pushed downward, as though squeezing out her abdomen.
“Expel your offspring, slime.”
“Ah, ahh....”
“It’s all right, it’s all right. There’s no need to be so afraid. We only need to check.”
I slowly ran my thumb over the womb-shaped pattern carved into Casey’s vulva.
“You’re not going to tell me who was behind the attempt to kill me, are you? If that’s the case, it would be far more useful to keep you producing soldiers for our Vampire Legion.”
“No—”
“Shh.”
I roughly clamped a hand over Casey’s mouth.
“Wouldn’t it be better for you to become a factory that loyally produces soldiers for the Vampire Legion, even as a spy, rather than remain a spy who tried to poison me?”
“Ah, ahh....”
“Or will you reveal who was behind it? Who ordered you to poison me. Confess and find the light.”
I met Casey’s eyes and smiled broadly.
“Will you reveal the truth and end it all with one slime-birth show, or will you become a factory that gives birth to slimes forever?”