[Brainwashing, Corruption, Roboticization]

"At last! It's finally here! My brand new gem set!"

The excited voice of one Tohsaka Rin echoed through her otherwise empty manor, followed by her happy giggling as she grabbed her package and dashed into the living room. She had been waiting for this day for quite some time, as her supplies had run low following everything that happened during the Holy Grail War. Now that she had the freedom to practice her Magecraft once more, and the funds to properly support the extreme cost of her family's specialties, it was time to try out the highest quality gems that she could get ahold of.

She rubbed her hands together as she sat down on one of the many couches that dotted the very empty room, not even paying attention to how light the package had been when she ran into the room. She was too ecstatic at receiving the damned thing to use her brain for even a moment. A trait that quite a few people had taken advantage of during the war, but that stuff was in the past! Surely she couldn't be tricked by a simple transaction, right?

Rin's eyes beamed with excitement as she tore open the wrapping and the packaging itself, only to feel her heart sinking and crashing as she realized that she hadn't received a set of gems. No, she had received exactly 1 gem. One single, solitary gem. And it didn't even look high quality, being a deep pitch black with an amber-like frame snapped to it. It wasn't even a pure gem because of that...

"Ah... I've been made a fool of again." She muttered as she slumped over in her seat, feeling the crushing sense of defeat filling her heart. If she had bothered looking closer at the offer, she would've realized the text on the website she had been buying from didn't guarantee anything, and that it was a special 'drawing' offer. She just received one of the worst prizes you could get from that, or at least it seemed that way...

The heartbroken magus picked up the gem and looked it over. To the naked eye, it seemed like just another ordinary gem. Nothing particularly special about it. It could even be a very polished cut of obsidian, and she wouldn't be able to tell. But there was something about it. Something that pulled her in the more she looked at it. Seeing her eye reflected in it, slowly turning-

Rin put down the gem, her mind shivering. "What just... What just happened?" She muttered in a quiet tone, feeling her body growing cold thanks to the way her eye had suddenly turned a deep red after reflecting in the pitch black gem.

She darted up from her seat on the couch, heading straight for the nearest mirror, only to breathe a sigh of relief as her eyes looked positively ordinary. Maybe she was just seeing things. Maybe it was the stress put on her mind from being scammed that badly. Yeah, that could be it. Maybe she should just sit down and try to think about what the gem could do...

The black-haired girl sighed deeply as she walked back to the couch, sitting down once more as she looked at the gem resting on the table. It had done something to her, or at least taken advantage of her weakened mind. So maybe it had captivating properties, ones that could help her ensnare those that belonged underneath her heel...

Rin thought about it for a few seconds, before brightly blushing. How did her mind run away with such a thought? That wasn't the kind of girl she was. Sure, she shook Emiya around a couple of times and made sure that he understood where he belonged in the pecking order, but he didn't treat him like a pet. Even though she really should've, considering the power that was at her disposal...

Her heart skipped another beat. Thoughts that weren't her own, thoughts belonging to somebody who was so much more sure of themselves... They were invading her mind. And that wasn't the part that worried her most of all, it was the fact that the gem still sat on the table, just gleaming ever slightly as the light reflected off it, beckoning her to pick it up...

"...I shouldn't. I really shouldn't." She muttered to herself as she got up from the couch again, taking slow and delicate steps towards the exit to her home. The rational part of her mind, the part that had survived the Holy Grail War, was screaming into her ear. It told her that all of this was worthless, that she should get ahold of Emiya and make sure that nothing terrible happened to either of them...

Unfortunately, that part of her was painfully quiet compared to the beat inside her heart. The whisper of glory that had started filling her head, courtesy of the thoughts that had invaded her mind. "The power..." Her voice grew deep for a split second as she whispered to herself, turning around to face the table once again. If she took it, and it had the power that her mind imagined...

She could conquer everything. She could show the world, and especially those that dared look down upon her for everything that had happened in this city... She could show them exactly where they belonged. Underneath her heel, begging for mercy. Begging to be made into her toys, or worse than that. All that she had to do was pick it up, and pour her magic into it. Then her wishes... The wishes of a powerful Magus, could come true.

Rin's heart pounded against her chest. For every step she tried to take towards the exit, two more were taken in the direction of the table. She wanted to run, but she wanted the power to stand alone. And eventually, the latter desire won out, as she hovered right over the blackened gem, her arms shaking as she kneeled down to pick it up.

Her face reflected in the palm-sized gem, her eyes turning red upon prolonged exposure. She could feel her teeth clacking together, the fear of what could happen to her if she tried to use it properly. She could feel the sparks of anticipation spiking down her spine, waiting for her to do something, anything with it... And she couldn't resist that temptation.

Thus, her eyes closed. And from her hands, a gentle glow emerged. She poured her magical energy into the gem, just like she would any other jewel that she had once used as ammunition. She needed to charge it, so it would function at full power. And then, she'd get what she wanted...

A scream left her lips as the effects of the mana transfer lashed back, causing no end to pain as the center of the gem started to glow. Gold was being carved into it, in the shape of an eye, as it sucked out more and more of her mana now that she had opened up the flood gates. All while her breathing grew heavier, and her eyes started to flicker. Her vision was blurring, and she regretted falling victim to its temptations...

-ADMINISTRATOR REGISTERED.-

A message flashed through her mind. A cold message, devoid of emotion. Devoid of care. She wanted to question it, but the light of her own mana started to flood from the gem as the golden carving finished. The 'eye' opened, and the gem started floating out of the amber that tried to contain it. All while the girl could do nothing more than look at it.

-INITIATING MERGING PROCESS.-

The gem flew towards the girl's chest, disintegrating her outfit as soon as it made contact and sinking straight into her body, causing her to let out a scream as the pain from before intensified... Only for it to vanish moments later, leaving behind only a chilling sensation across her entire body. And humiliation, considering that it had taken away all of her clothes by disintegrating them into particles too small for the naked eye to see.

-PROCESSING-

Her heart was beating. Constantly, though not at an intense rhythm like before. Now it was more like the beat of a drum, causing her body to react as it pounded against her chest. The more it pounded, the more she could feel everything growing colder. And it wasn't because of the wind in the room, it was because...

-CONVERTING ORGANIC MATTER-

She looked to her chest, and the first thing she saw was the gem poking its way out right above her bosom. The next was the way that her skin turned from flesh and blood to hard metal, blackened tones reaching across her body in a matter of seconds. It wasn't just ordinary metal either, as there were spots on her body where the plates split and extended, making her seem less like a solid chunk and more like a robot...

Rin's eyes followed the spread of metal along her arm, flexing it as she watched half of it get turned a gold-trimmed black, with the plates forming what seemed to be a sleeve as it reached all the way out to her wrest. Her fingers were individually converted, with a joint for every single possible bend she could humanly achieve, as well as enough flexibility to achieve bends that she never imagined. If she wanted, she could grab things on the back of her hand...

Not to mention the power that flowed through her now mechanical fingertips. It was something beyond just a burst of mana. It was like every time she breathed, something that was wholly unnecessary now, she could feel the mana pumping through her. Filling her. Fueling her. She never felt more alive than in this one moment...

The spread of metal continued further down her naked body. The panels were sleeker around her torso, to give her a humanoid feminine form instead of a solid slab of pure machinery. Not only that, but it seemed like a second layer of panels formed on top of the inner, making the outline of a long dress that reached all the way down to her feet, hiding away the panels on her legs that mimicked that of her stockings. Thus, permanently solidifying her beauty and emphasizing it.

Having her body turned into metal and yet still carry the grace of her former human self was nothing short of a miracle. One might even call it perfection. An Administrator Unit like her deserved only the most perfect combination of metallic superiority with the elegant form of the fleshy ones...

-REWRITING MEMORY BANKS-

...Administrator Unit. That was what she was becoming. At least, that was what the gem in her chest told her. No, not becoming. She had always been one. Her memories were being scrubbed clean faster than she could process them, and her existence as a whole was being utterly overwritten. And the best part of it all... She was wholly conscious the entire time. She didn't resist having herself rewritten like this, feeling the power pour through her with a grin on her face...

Rin's grin froze on her face as her head was the final part to be converted into the elegant mixture of black and gold metal. Just like the way that her body had been covered in sleek metal that gave her the look of an empress wearing her proper gown, her hair was just as properly converted. While she didn't have flimsy individual strands, she did have enough joints in every single bit of the 'hair' to make it as seamless as it could be.

The roboticized woman breathed in deep as she felt the power running through her. She let one of her fingers slowly glide down her chest, exposing her bosom in all of its soft metallic glory, both orbs now twice as large as they had been when they were fleshy. That very same finger then slid further down, parting the midsection of her skirt to expose her inner thighs, which were just as delicious in this soft-metallic fashion as the rest of her body. After all, an Administrator Unit like her had to make sure that everyone was looking at her when she gave them her commands...

-CONVERSION COMPLETE. REWRITING COMPLETE. ADMINISTRATOR UNIT RIN CONFIRMED. NEW DIRECTIVES AVAILABLE.-

Her expression turned from a delighted grin to a wicked one as all sorts of wonderful options appeared on her HUD. Her golden eyes gleamed powerfully as they hit a specific one. One fit for an Administrator looking to show her utter dominance over the world. The duty that she was made for...

-DIRECTIVE CONFIRMED. NEW DIRECTIVE: CONVERT MANA-FILLED ORGANIC MATTER INTO PROCESSING UNITS.-

Rin laughed as she took the first step outside of her pathetic home, a new purpose filling her heart. As the eye of her central unit, embedded in her chest, gleamed with ambition.