Rin Tohsaka and the Tentacle Monster[Fate/Stay Night/Tentacle Pet CYOA] – Chapter 1
Tags: Tentacles, Non-con, body-modification, pregnancy, genderswap, futanari, corruption,
Summary: A month before the Fifth Holy Grail war is about to occur, Rin Tohsaka decides to practice summoning and accidentally ends up summoning an evil tentacle monster(based on the Tentacle Pet CYOA).
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Rin Tohsaka was a genius.
Now, that was an obvious statement and did not need to be thought or stated out loud, but sometimes it was good to remind herself of that fact when did truly something she had heard some of her fellow students called being 'big-brained' and that being so clever you even surprised yourself.
That was the state Rin found herself in, as due to the Command Seals that had appeared on her hand, she knew that a Holy Grail was soon to begin, where a Magus like herself would summon up a Servant, the most powerful form of familiar to aid her in winning the Holy Grail.
So, in preparation for that, Rin had a simple thought.
Why not practice?
Normally, a magus made their own familiar via using dead animals and other things. However, one could still use already existing and living creatures into your familiar and summoning rituals outside of Servant ones. A few weeks ago, while going through storage she had found a book about summoning creatures from another dimension.
And since that sounded very similar to summoning a Servant from the Throne, she was gonna try that.
And now, after setting it up, she was in the middle of chanting in Latin as the book had been written in that, and while she knew the language, she wasn't the best at it. But she had gotten the gist of the specific ritual, which was meant to summon a creature that could take care of one's needs.
And man, she could really make do with a Magic Butler.
Unfortunately, Rin Tohsaka should have read the back of the page to learn what needs the creature took care of.
The circle glowed with purple light as the liquid she used to paint it had been mixed with grapes as that was the ritual had called for.
And then she finished, the magic circle exploded in rainbow light that had Rin cover her eyes to prevent herself from going blind.
After a second, she removed her arm to see what she had gotten and raised an eyebrow at what she was seeing.
As in the middle of the summoning circle laid what looked like to be a massive slug? Creature that was white in color and filled out most of the summoning circle.
It kinda looked like a bean bag, if Rin was being honest.
"So, how are you going to help me out?" Rin asked as she kneeled down and poked the harmless-looking creature that she had just summoned. Had she messed something up? Though she had to admit it was kinda adorable looking as she now petted what looked like its head as growing from its side looked to be a pair of sensory stalks. Rin suddenly heard a squelching noise, and her attention was brought to the slug's back, were she saw white tendrils? Emerge a little over a dozen, and was it her or were they shaped like-
"What?" Rin shouted in surprise as the white limps that had emerged had, with surprising speed, wrapped around her own limps(she could feel the warm slime they exuded on her skin), lifting her up into the air. "Hey, what do you think you are doing? I am your summoner, your master- urgher!" Rin started to rant, but it was caught off as one of the tendrils pushed against the lips of her mouth and then forced itself past her teeth and down her throat thanks to the slime it was excreting and it was in that moment Rin realized these weren't tendrils.
They were tentacles.
She had just been a god's damned tentacle monster!
Rin tried to turn on her circuits to vanquish this perverse creature, but her concentration was broken as Rin felt a tentacle press against her lower lips before entering her pussy tunnel and smacking against the entrance to her womb.
"Hmmm." Rin moaned around the tentacle that was in her mouth as it was clear this creature was deadest on raping her, with more tentacles emerging from its slug body that tore off her clothing, giving itself full access to her body.
The tentacles continued to her in the air as the ones in her mouth and pussy began thrusting their lengths in and out of her body.
Rin couldn't help but moan harder at the act as, despite the mental denial she was subjugating herself to, she was getting very turned by having her holes violated by a creature her pussy having already squirted once from having the tentacle cock smack against her cervix.
She had never thought seeking anything would feel good, but apparently, it did, though what Rin didn't know was that it was thanks to the aphrodisiac slime that was being secreted by the tentacles slime that was being slowly pumped into her.
All the while, other tentacles were molesting her body further; two had circled around her armpits before their much thinner ends, the heads very different from the ones that were currently inside of her mouth and pussy as their heads had been very obviously shaped like a dicks, but these one were more coned shaped as they encircled her breasts.
The slim appendages teased her hard nipples while another was flicking her erect clit back and forth, sending jolts of pleasure as she continued to get violated by tentacles, her body cumming over and over again as her minutes ago virgin body was capital f, Fucked by the creature that she as summoned to be her familiar, but if walked into the current scene such as her Mother who was sleeping upstairs they would see that she was currently not the one in charge.
As usual, Rin Tohsaka had gotten ahead of herself as due to only having read the first page and poorly, she did not notice that further instructions were on the back of it, such as how to lay down conditions for what kind of sex monster was summoned and even a time limit for how long it stuck around. And so Rin Tohsaka had rolled the Gacha and gotten an SSR Hentai Monster, that would forever stick around. That could act on its own initiative, and while it was a sapient creature capable of thought, it ruled by one desire, and that desire was to procreate and multiply.
And so the, at this point fucked silly magus could only moan as she felt hot cum be fired down into her gullet, the thick substance swelling her stomach as two rooms in her stomach were pumped full, the slime she had secreted in having made body already a little more elastic, and if Rin were a bit more coherent and used to the pleasure of Tentacle sex, she would be able to feel the cum assault the singular egg that had been dropped into her uterus earlier this morning.
With the egg beginning to divide the second that it touched the side of her womb and attached itself to the membrane even as it was bathed in the cum of the tentacle monsters, the egg now devouring the mana-rich semen to fuel its own growth, doing the same for the cum that was being digested in Rin Tohsaka's stomach.
Rin whimpered as the tentacle in her mouth retracted; as she wanted to taste the delicious member again, her mind was not even able to question how she had been able to breathe with it down her throat for the past thirty minutes.
Though she did giggle as the body of the slug changed shape, the back of it opening up to reveal a bed of small nubby feelers that tickled and massaged her front body as she was laid down, all the while the tentacle in her pussy stayed in place looking all the semen it had pumped to prevent it from leaking out.
And with her body comfortably situated, Rin started to feel sleepy from the pleasant buzz her body was experiencing as the nubs that teased her body slowly moved across her smooth skin.
All the while, the tentacle monster moved across the floor of the basement, heading for the stairs; all the while, the tentacle in her pussy moved slowly still as on the spot where her womb was located, a mark started to form, one that would normally be located on the summoned monster but Rin Tohsaka had not fully filled that part of the summoning contract, and so the relationship that would have been established had been reversed.
The Tentacle Monster was now the Master, with Rin Tohsaka being the 'pet.'
Eventually, others would be claimed, as well as the consciousness that had been imbeded within this tentacle monster by its creator had been from a human in another world for those that wanted their Hentai Pet to have sapience.
And he now had an opportunity to enact his most perverse fantasies with the tools at his disposal.
"Thank you, Rin, for giving me this opportunity; I shall be sure to make you into my perfect slut," The Tentacle Monster said as he laid her to bed, as he wanted to indulge in some trolling first.
He removed the tentacle cock from Rin's pussy, the girl unconsciously moaning in disapproval before he decided to hide underneath her bed.
Rin's mind would not remember the words and actions her mind had picked while she had started to fall asleep.
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A/N: So this is the first chapter of fic in the same style as A Hero and His Wolf, with Fuyuki getting corrupted by Hentai, this time it is a Tentacle Monster with the mind of pervert from our earth, debated of doing this, a SI, but decided against it, just an OC who just wants to fuck and corrupt, whereas 'I' would want to try and help. So this is kinda the Opposite Version of A Hero and his Wolf.
Instead of a Wolf that just wanted everyone to achive sexual pleasure and happiness, this is an 'evil' tentacle monster that just selfishly wants to fuck and fuck around.
So there will be no PoV from the monster itself, just people interacting with it and getting violated and changed by it.
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