[Size Difference, Breeding, Hyper Pregnancy, Fertile Bodies, Weight Gain, Farts]

While the concept of a Servant is well known to most of the Magical World, the idea of using them outside of the Holy Grail War ceremony is absurd due to the sheer amount of Mana that needs to be used to keep them manifested. However, that doesn’t really matter if you find a way to offset those costs through a couple of loopholes.

Kiara Sesshouin, a depraved nun with eyes on making the world devolve into depravity through intercourse to the point where several versions of her across the different world lines nearly accomplished their goals, was one to turn towards these loopholes. The primary issue in regards to keeping a Servant manifested was Mana, but who said she had to supply all of it?

That was why she had summoned a demon to this world. Something to bind to her like a familiar, with a special give-and-take kind of relationship. He provided her with all the mana that she could possibly need, and she took on a form that grabbed his attention the hardest. So what if it was a younger form with her curves emphasized, especially those meant for rearing children? If it got him hard and it made him produce the mana she needed, then it was all she could ask for.

After a few nights of the two getting as comfortable as they needed, the next step was to summon a Servant. Thanks to her dearest demon giving her a taste for the kind of childish flesh that she now inhabited, she couldn’t stop herself from picking a Servant with the same kind of traits. Especially the fertile ones, since there was one more step to her plan.

Jack the Ripper, the Assassin-class Servant that served as a manifestation of many orphaned souls, materialized in front of her… And was promptly forced to the ground by her demonic accomplice, putting her adult-sized ass to good use as he rutted it into the night. But this time, it wasn’t to supply mana. It was to fill her with an essence that his Summoner had concocted, one that would make the cost of keeping her in this world nill compared to the output she’d provide.

Her body would take in the mana that the Demon provided, slowly making her shift in shape and size as it grew accustomed to her body. All while being filtered through a spell cast by the child-sized perverted nun, turning her into little more than a beast wearing a girl’s skin as her own.

The fruits of these efforts would take time to show, but Kiara had plenty of time to see it all pan out. Especially since her demonic cohort was more than willing to keep going as long as she kept him company. Whether or not he wanted to whenever she came at him when he was ‘busy’ with something else was a different matter entirely.

Life between the three was a defiled one, and everything would come to a head a few small weeks later…

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“Papa, Papa!”

The excited voice of the Assassin-class Servant echoed throughout the bedroom that had been prepared for the Demon, her body quickly causing the bed to shake as she leapt atop of it like an excited puppy would, especially when she wanted to wake her owner from his comfy nap.

“Tryin’ to catch a bit of shut-eye, Jack, can’t ya keep it down a lil’?” The demon, a dark-skinned bunny-eared lad by the name of Jermod, groaned a little as he slowly sat up in bed, only to feel his cock shooting up to prime erectness at the sight of what was in front of him.

If he knew that this was how his plan with Kiara would end up, maybe he would’ve turned it down. Because he couldn’t really keep himself from indulging himself whenever saw her climbing onto the bed, making the poor thing creak as she dragged her enormous tummy along the side of it.

Compared to when she had first been summoned, Jack was positively massive. Her hips and her ass, which had already been overly developed for a girl of her size, now covered nearly half of the bed by themselves. Heck, he had practically been swallowed by the crevice between those two mountains one time when she decided she wanted to sit on him and squeeze his cock dry with her thighs. And despite most of her lower body being that huge, it was lopsidedly so as her breasts and her arms hadn’t gained nearly as much weight.

Her belly however, now that had been through its fair share of changes. Thanks to the combination of the Nun’s terrible spell making every single one of her eggs active and keeping them infinitely replenishing to ensure that she could breed for literal decades on end, as well as the demon bunny’s natural virility knocking up three eggs per sperm cell, and the size of her tummy just ended up being a natural thing. It hadn’t even been a month, but if she were to lie down on one side of the bed, her ass and thighs would take up one half of its width and the belly would take up the rest plus a few extra inches after that…

But all of those changes were just parts that had grown. The real change came in the form of the more fur-like parts added to her body. Soft carpets of fur had grown along her legs all the way up to right above her hips leaving an angle of them uncovered so they pointed inward towards her crotch and left most of the oversized wobbly mounds she called an ass smooch at the same time. Her arms were covered in plenty of that fluff as well, reaching all the way up to right above her elbows.

Those furry parts didn’t end in human feet and hands either. Both sets were replaced with beastly variants, akin to a cross between a bunny and a wolf’s paws and claws. Combine that with the rabbit ears poking out of the top of her head where a wolf’s ears would be, as well as a soft mane of fluff having grown around her neck, and she looked more like a beast than anything else. Just as her Summoner had intended.

While Jermod had been busy eyeing that wonderful body that the little girl had managed to acquire, he definitely hadn’t noticed that she had begun licking the tip of his cock with the same kind of gluttonous fervor that she had whenever she ate her own weight in meat…

“Ara, getting ahead of yourself again, Jack?” Kiara chimed from the doorway to the bedroom, dragging herself inside just the same as her ‘Servant’ while licking her lips. Of course, whenever one of those little ladies appeared, the other one was right behind her…

Her body was almost the same size as Jack’s at this point, cultivated through a thorough diet of demon-filled semen, but the main difference came from the lack of demonic features decorating her body. Every part of her enormous form was entirely ‘human’, though the validity of that was very hard to argue. Especially since she showed an appetite at nearly the same inhuman level as her Servant…

Jermod let out a sigh and a half as he felt the bed creak louder underneath, the two girls crowding around his cock with their bellies dragging along the mattress underneath. It was a wonder the two weren’t stuck atop their massive domes. And a wonder that he hadn’t blown his load already, maybe the drowsiness still inside his body was giving him a bit of trouble in that regard.

“Fine, if you want a morning snack, who am I to stop you?” The black-skinned bunny grinned a little as he put his hands on the two thoroughly bred girls’ heads, guiding their tongues along the sides of his shaft in unison. All while his cock throbbed as he heard the sounds of their bellies slowly grow louder, something churning within the pits of their stomachs…

The longer they dragged their tongues along his shaft, the more the taste of his cock managed to agitate their bowels. While their brood wasn’t yet awoken by their usual antics, the ripples that started running along the diameter of their tummies was almost comparable to when those kids started acting up. The rumbling that came from those domes was just as loud as a lion’s roars, signifying one of his favorite parts of having the two girls being by his side like this.

Both Jack and Kiara’s expressions turned into ones of pure bliss as their cheeks rested against the stiff shaft, while their asses parted to release the gas kept stocked inside their bowels. The tuba-like orchestration of their farts always caused their thighs to ripple and wobble just as much as when he slammed his rod as deep into them as it could go, making this display all the more exciting…

And though their bellies started to shrink ever slightly whenever they let out that much gas, they quickly filled right back. Their diet of specially prepared meals designed to enhance their libido as well as generous dollops of demonic seed kept them gassy for days on end, just as the demon liked them. And whenever one of them got too aroused by having their holes spread apart so wide by their gas…

“Papa, Papa!” Jack cried out again as she pulled herself off that wonderful shaft, swinging around with surprising deftness as she presented her pungent posterior and the thoroughly wet slit parked not far beneath. “Playtime!” She chimed as she grabbed her buttocks and spread ‘em, letting the smell grow stronger while also exposing that fertile hole that much more.

Jermod grinned as he got up properly and pushed the tip of his cock, the whole thing being roughly the same length as the girl was tall, into her awaiting folds. “Papa’ll give you what you want, since you asked so nicely for it!” He cried out, putting his hips to good use as he slammed straight ahead.

Her moans were loud and quick, her eyes rolling into the back of her head as her body trembled all over. The sensation of being rammed into like this was enough to make her brood awaken, causing several of them to kick against the inside of her womb and make her tummy ripple all over. The rougher they were, the more fun she had being fucked by her ‘Papa’...

Kiara didn’t need to say a word, just adjusting herself to push her massive belly up against her cohort’s back while she gave that dome a little slap. Within seconds, her own brood started bouncing around, kicking and punching with all of their might to goad the bunny demon on. After all, the sensation of having your kids cheer you on, so to speak, would make anybody breed even harder.

Jermod could feel the slight hints of pain caused by the children within the nun’s tummy kicking him, and that just made his cock throb and grow bigger inside the Assassin’s womb. He put all of his power and his lust into his thrusts, slamming into those fat cheeks and the thunder thighs they were connected to without as much as thinking about if she could be hurting her. Because his demonic instincts to breed had taken over, just like they always did.

Whenever he got like this, it barely took more than a minute for Jack to cum. She felt like she could pass out at any moment from the delight of being rammed like this, and the way that her pussy squeezed down on his rod quickly caused him to cum not long after, which would just make it harder for her to stay awake thanks to the assault on her senses.

The demonic bunny felt his balls contracting as he let out a torrent of cum that fired straight into the girl’s open womb, filling the oversized birthing chamber with even more of his seed. It’d keep the kids fed, and whatever bits of it managed to reach all the way back to her hyperactive ovaries would ensure another batch of kids growing within her…

Just as he was about to pull out, satisfied with the way that he had fertilized the beastly girl’s appetite, he could hear the teasing whisper of his Summoner, immediately making his cock grow erect once more…

“Round two, chocolate bunny. It’s time for my hole to swallow you whole…”

To say that he did as she asked would be an understatement. And to imply that he was done with them after just one fuck would be an outright lie. There was still so much depravity for them to partake in.

And once Jack had been fully converted into a demon, it would be time for them to grab another Servant to corrupt...