[Nylon Addiction, Brainwashing]

"...Da Vinci? May I kindly ask what you are doing?"

In the clever-minded Caster-class Servant's workshop stood a familiar eggplant-haired girl, staring straight ahead at the owner who seemed to be... sewing something? An unorthodox timesink for sure, especially considering the kind of antics that the brunette usually got up to.

"Oh, Mashu. This?" Da Vinci replied with a smirk as she motioned towards a set of tights being sewn together by a magic-powered sowing machine. "This is something I wanted to try and make, ever since we saw our dear Master wearing such formal clothing when they were stuck in Shinjuku. Seeing them that off without hesitation made a little fire spark within my heart, and I just had to try something out." Her smirk widened more than a little as she turned back towards the machine, rubbing her hands together.

The purple-haired Mashu Kyrielight felt a little sweat run down the side of her head. "I... I see. It wasn't that impressive, you know. It was just bait used to lure out that Assassin..." She sounded more than a little nervous as she tried to downplay the importance of the event, which just prompted the Caster-class Servant to laugh in response.

"If it wasn't such a big deal, then it wouldn't have struck me like a lightning bolt! Now, you should leave. I have to put the finishing touches on this pair. If everything goes according to plan, I'll be able to fit into a nice dress and look just as stunning as they did!" A slight cackle left the painter's lips, making it clear that she was going just... the tiniest bit crazy.

Her guest blinked in shock before silently sighing, taking her chance to leave as she hoped that this would all be over soon. Best case scenario, it would turn out to just be a pair of normal tights that she was trying to hype up, like a few of the occasional inventions that she tried to pawn off on her fellow Servants. She hoped that it would just be like that...

Da Vinci scoffed as she turned off the sowing machine, smiling to herself as she pulled the finished pair of nylon tights off the needle. "Perfection. Sure, a true woman who knew her craft could probably sew something more beautiful, but this will do for the time being." She muttered, acknowledging her own bias towards the handicraft of the old ways while holding up the legwear to let it soak in the light above.

Barely any rays from the bulb managed to squeeze their way through the tightly woven fabric, and those that did were just barely able to rain down on her face without being shadowed by the tight holes they had to travel through. They were made to be dense, yet still loose enough that it wouldn't be a problem. They needed to be good not only for general wear but also for the visual aesthetic. She was an artist and a budding engineer at heart, she needed that special blend of practical and pleasing to the eye, and judging by the smile on her face, she had achieved it.

"Now, to see how this feels..." The Caster-class Servant said to herself as she gently removed her legwear, letting both stockings and shoes fall to the floor as she gently slipped one of her feet into one of the leg holes in the brand new tights. Immediately, she felt a shock run through her entire body as it felt as if the fabric was actively creeping up against her skin. She passed it off as just sheer wonderful craftsmanship as she pushed her foot deeper while tugging on the sides to make sure that everything was properly aligned.

Once her left leg had sunk in accurately, then came the right leg... and immediately, the shocking sensation returned. But this time, it wasn't just because it had reached a standard most humans would find unattainable. No, it shocked through her skin and her body... because the nylon was outright sinking into her skin. Becoming a part of her. As if it was some sort of symbiotic entity, seeking a host to leech and support...

Da Vinci was shocked on one hand and utterly fascinated on the other. She felt the tights creeping up her body until they were attached by the waist, snugly clinging to her skin just like any other pair of legwear. But she knew that it wasn't natural. She knew that she had done something to give it a form of autonomy. Perhaps she poured too much magic and too much of her current obsession into the machine that had sown the entire thing together. But what she did know, something that made her heart throb with every passing second was that she liked how it clung to her body.

That positive emotion was enough for the tights to feed off, causing them to slowly creep further up her body. She could feel the fabric tickling against her stomach, causing her to bend over as she giggled loudly. She could feel it grazing against her sides, causing her legs to shake from the wonderful sensations. As it reached her arms, it managed to spread all across her limbs in mere seconds, even her fingertips being covered in the strange self-serving fabric. Finally, it stopped as it reached her throat, leaving her with only her face and her head left uncovered by the nylon. She hadn't even noticed how her outfit had been consumed by the fabric in the process, leaving the Caster-class Servant practically naked underneath the soft layer.

"This... This is... Oh my goodness..." She immediately launched into heavy breathing, feeling every hair stand up on her body as her breath grazed against her 'second skin'. She had become much more sensitive, thanks to the mutual relationship between the clothing and her body. If she didn't know any better, she would've thought that they had become one entirely. As if it was permanently a part of her.

To test this theory out, the Caster-class Servant closed her eyes and tried to focus on the tights receding to a more... presentable point. She could feel it peeling back down her body at an excruciatingly slow pace. So much so that she felt her nipples stand fully erect, preventing her from concentrating. Her eyes shot open mere moments before orgasm, as she noticed that the nylon had indeed receded. Only to return to her neck once she lost all semblance of concentration, and the juice from her subtle orgasm slowly ran down her nylon-covered thigh...

Simply put, Da Vinci was utterly charmed by the prospect of having a pair of tights that responded to her way of thinking. Not just that, but it felt oh-so-wonderful to have it pour across her body like a liquid. She could feel it pulsating in response to her heartbeat, causing her arousal to heighten yet again. Her near-permanent blush was a clear display of how wonderful it made her feel.

In fact, why did she need anything else? She just needed her precious tights, she needed them to play with her at all times. She needed them to make her even more beautiful, to the point where nobody would ever question her looks. Yes, she didn't need anything fancy like what her Master had worn, she was perfectly content to wear the one piece of clothing that mattered above all else. Her tights.

But, how could she possibly make people understand the true power and love that her tights possessed? She needed somebody that she could spread the love to. Somebody who could see eye-to-eye with her new way of thinking. Her proverbially nylon-obsessed thought-process. Something... somebody like...

Ah yes. Mashu. The Shielder-class girl who always stayed behind, now that her powers were in flux. She'd look wonderful in tights that would cup her petite body. It would honestly and truly make her beauty stand out. If she just were to tell her that her Master would love to see her dress like the nylon-obsessed painter, then she would easily go along with it. It was a fool-proof plan, something that nobody except for a genius like her could've thought up.

Now, she just needed to catch her alone.

---

This wasn't the first time that Mashu had been caught off guard by the way that Da Vinci behaved herself. She had been surprised earlier in the day, wondering why she would take up sowing if it was just for a brief interest. She had also wondered why she was obsessed with the outfit that her Master had worn, but that just ended up leading into the sowing.

Now that she was faced with a nylon-clad Caster who had managed to pin her against a corner in a room, things had changed quite rapidly. "D-Da Vinci? I... I have to ask you, what's with that attire? And more importantly, can you please move? I need to go check up on Master..." Her words really conveyed how unnerved and uncomfortable she felt at that moment in time.

Unfortunately, the nylon-obsessed woman did not care. "Oh, I don't think I will, my dearest Mashu. You see, I think you need to realize just how wonderful all of this feels..." The brunette chimed as she gently pushed her knee up against the younger girl's crotch, pressing it inward to make sure that she was making contact between her nylon and the eggplant-haired girl's nether region.

Immediately, a moan slipped out of the bespectacled girl's mouth as she felt a little bit of juice staining her panties. She didn't know that it was possible to be driven to such a high level of arousal by a single touch, but she did know that she didn't want to admit how turned on she was. Not that she needed to, as she felt a massive shock run through her system. "W-What's h-happening?"

Da Vinci merely smiled as she pushed her knee back into the warmed crotch. "You're growing to be just like me, Mashu. You'll be one with your very own set of nylon tights. And you won't even have to ask for it, you just have to sit still and cum, and it'll all be over." The words that left her mouth sounded more than a little deranged, which didn't help matters at all.

Mashu looked down at her body, feeling the juice from her pussy running down her thighs... and in turn, the nylon that had been spreading from the woman's knee continued to caress her body. From simply replacing her panties with itself, the fabric had grown further down to the point where each individual toe was completely covered in the living substance. She would be covered from head to toe in nylon in a few minutes...

Yet, even though she should be feeling fear at a situation like this, where her entire being could be compromised by something alien that would erase her good-natured soul and replace it with something perverted... She felt nothing but pleasure. Her cheeks were flaming red as her hair slowly grew out, the symbiotic nylon making her take on aspects of the prime host. The longer and the further it spread, the more she started replicating the Caster's appearance.

As it crept all the way up to her neck, and as her hair reached the same length as Da Vinci's, she let out a wonderful scream. The vibrations of her skin and her new second nylon layer matched each other, leaving her weak in the knees as she collapsed. The only thing that kept her 'standing' was the knee that still pressed up against her crotch, leaving her to look straight up at the perverted painter who had started all of this.

"Now, do you see what's so perfect about nylon, Mashu? Don't you think we should be sharing it with others? Maybe even our dear Master would love a set of their own." Da Vinci was smiling from ear to ear, letting out a little moan of her own as she felt the nylon practically slithering across her body...

All the young girl could do was nod, her eyes turning into hearts as she became one with her own nylon. The first of many girls that would fall to the Caster's newfound obsession.