[Genius TF, Brain Drain, Genderswap]

"Mikon! I can't believe you'd want my help, Da Vinci! I'm very glad to help you, but you have to remember. I don't plan on making anything difficult for my husband. So if you try something like that..."

"Don't worry, Tamamo. I have no plans to steal or inconvenience her. I wouldn't dare to get in the way of Chaldea's lone Master. All of this is merely to have somebody to converse and spar with. That's all."

"I see, I see! Well, why don't you tell me a little more about what you have planned? You're such a clever woman, and I can barely wrap my head around what's in that brain of yours. Just tell me what you're plotting, I promise I won't spill the beans or anything."

Leonardo Da Vinci. One of the first Servants to be summoned to aid the organization, and the only one to stick around properly. But that meant that she was also the loneliest of them all. Not in the physical sense, but rather in the intellectual sense. It wasn't like there were many Servants that were able to reach her level of intellect. And the ones that did... Well, they were complete maniacs in their own way. Whether it was because of their obsessions with their fellow geniuses, or the lengths they were going to go to reach greater knowledge.

No, she needed somebody that was on her level but remained nice and quaint. Somebody like Tamamo no Mae would do nicely. She wasn't exactly the smartest Servant, but she was very clever. She was able to set up several fights for the sake of keeping her Master all to herself, and that wasn't even getting into the other versions of her that wanted to scheme their way to the Master's heart. She was the perfect one for her to converse with. If only she was as intelligent...

But that was exactly why she had been called upon. Because she could compensate for the areas where her dear Tamamo was lacking. She could compensate for everything she was lacking, all through one of her devices. And thanks to the volunteers that were hanging around in the other room, she was ready to put everything into motion.

"Do you want the short or the long explanation?" Da Vinci asked, all while carefully taking a sip from her coffee. Oh, that was another thing that she would gain from a better partner. Somebody that knew how to handle the balance of flavors and heat for her coffee. Ever since Roman left them, nobody was able to brew her a cup that was just right.

Tamamo chuckled as she spread open her fan. "I'll take the short one. I don't want to know all your secrets, and I'm sure you wouldn't want to spill them all out. Even now when you need me the most, ohoho." The tricky Caster chimed, her tail gently swaying as she leaned closer. "Unless you want to tell me, so I can tell my Husband as well..."

"Ahahaha... No, I wouldn't want her to know about this. If she found out, she'd probably try and use it for something terrible." Truth be told... Their Master was one of those types that was a bit too obsessed for her. It was why she didn't spend much time with her and spent most of her time inside of the workshop. "Regardless, take a look at this."

Da Vinci pulled out a simple little necklace with a set of ears poking out of the amulet that was connected to it. An unassuming accessory, especially as she wrapped it around Tamamo's neck and made sure that it was placed almost right where her heart would be. All while she kept smiling while the fox remained unaware of the true purpose of it.

"My my, a gift for my wedding with my Husband? You shouldn't have!" Tamamo couldn't help but giggle a little more, all while slowly prodding at the necklace. Right before a bit of shade covered her face. "Da Vinci, you didn't interrupt my time with my Husband just to give me a gift. I wanted that short explanation. Please, go ahead and explain."

Ah yes. Tamamo's darker side. That was also one of the things that Da Vinci had come to enjoy about her. But regardless, she had to clear her throat. "The necklace is merely a conduit for the full procedure. In layman's terms, I want to increase your intelligence and make you a genius on par with myself. And I hope to accomplish this by amplifying your current level of knowledge to the point where it can compete with my own. Do you understand, Tamamo?"

Tamamo smiled from ear to ear. "Not in the slightest, but that's more like it. So how do you plan to make this amplification work? As far as I understand, boosting something as abstract as intelligence isn't exactly an easy process. Trust me, I've tried. I had grown tired of how backward thinking Cat was, and tried to make her smarter. All that I got out of it was a bunny, and then I quickly lost hope because she was starting to look like those fake versions of me." She explained, shivering all over as the memories flooded forth. Why did Cat have to try on that damned catsuit?!

"It's not. But it doesn't need to be that much easier if we can cheat our way through to the upper echelons of intelligence." Da Vinci said, a glint appearing in her eye. "I didn't invent things just to fall to my knees and give up when faced with a difficult challenge. Now, follow me!" She cried out, as she finally got up from her chair and headed straight into the room in the back of her workshop. She had been leaving her hapless helpers waiting for far too long, and they were probably going to leave if she didn't start the experiment already. Especially since they weren't aware of how important they were.

"Aha! There you are, Da Vinci! Behold!"

Da Vinci grimaced slightly as she stepped into the backroom. Of course one of her guests just couldn't sit still. No, he had to do more adjustments to the device that she had invented. Because that was the kind of man that he was. At least the other one had fallen asleep while she was waiting...

It was Nikola Tesla. One of those aforementioned obsessed geniuses. In his case, electricity was his whole deal. That and his rivalry and feud with Edison. But given the additional sparks that were pouring forth from the machine that served to facilitate this entire process, it was clear that he had found a way to supercharge it while he was waiting.

And the other guest? Elizabeth Bathory. The ear-piercing dragon idol that was currently just dozing off on her chair, all while the electricity that sparked from the device behind her got dangerously close to piercing right through her and using her as a grounded connection...

"Ehhh? Liz and Tesla? What do we need them for?" Tamamo asked as she poked her head in, closing the door behind her just to be courteous. "I mean, Tesla's a genius, I can't really deny that. But why did you grab Liz? She's not exactly anywhere close to being a genius. Unless you're talking about her ability to break anything when she starts singing, that might just be a kind of genius..."

Da Vinci chuckled. Yes, that was true. But she served an important purpose. "Even somebody like her has her uses. Elizabeth! Please, wake up. We're about to start the experiment!" She shouted, clapping her hands together to make sure that the idol woke up.

Elizabeth yawned and stretched as she slowly rubbed her eyes. "You took so long, Da Vinci, I'm sleepy..." She yawned a bit more, as she almost started to sing from how sleepy she was. "Aaah.... What's the deal with all the tech anyw-"

She let out a shriek as the electricity behind her finally zapped straight through her, forcing her to collapse back into the chair with most of her body having turned a rather comical shade of charred black. Ah well, she could endure something like that. Once she got over the shock of it, anyway.

"Excellent! The power of the machine is at its maximum!" Tesla wasn't too bothered by the way that his modifications had ended up frying Elizabeth for the time being. No, he was more concerned with the output. "Da Vinci, if you would? We're as ready as we can be!"

It was at this point that Tamamo noticed something about the two 'volunteers'. Both of them were wearing a synthetic pair of fox ears that matched the ears that were poking out of the amulet that she was currently wearing. Even somebody like her could pick up on the connection between the two, which prompted her to whisper to Da Vinci. "Really, you designed all of this after my ears? How long have you been thinking of me exactly, Da Vinci?"

"Longer than you would even imagine." Da Vinci whispered back with a blush on her face. "Begin the experiment, Tesla!" She shouted, making sure to fit a pair of goggles onto her face so she didn't blind herself with the obvious amount of lights that were going to be sparking and bouncing around.

Tesla did as commanded, sending an extra powerful shock of his electricity into the device in the back. And almost immediately, he felt the connection to the machine turn on. He could feel the fox ears that he was wearing start to vibrate. "It's working! It's working!" He shouted with glee and delight, laughing with a sense of intense pride. Of course he would, it was something that would ultimately prove his superiority over that blasted Edison!

All while Elizabeth let out a cry of pain and... pleasure? It was certainly some form of moan, and it helped her shake off all the soot that had formed on her after she got shocked. "I-Is it supposed to feel this intense? I can't really understand!" The idol cried out as she tried to touch the fox ears on her head, only to let out another yelp as it immediately shocked her back.

Tamamo watched as the fox ears on top of both participants' heads started to animate. It was like those ears were truly part of them and not just an accessory. Extremely lifelike, just like her own ears. And when she slowly put her hand on the amulet that was pushing up against her chest, she could feel a current pouring into her. One that wasn't nearly as intense, but one that definitely couldn't be ignored. It was like... Something was being poured into her. All while she was breathing heavier and heavier...

Da Vinci was smiling. Yes, everything was going exactly as she had planned. The connection between the two donors and the receiver had been established. But nothing was currently being transferred. "Tesla! Pump more power into it! I need to see the effects pour through Elizabeth!" She cried out, making sure that he could hear her over the sounds of the machine nearly going haywire.

"W-wait, I'm not ready for that! Slow down!" Elizabeth cried out in turn, but her protests fell on deaf ears. Especially as she felt the pressure and the electricity pouring through her, right up until it felt like something just... Just...

*Popped*

A smile poured onto Elizabeth's face as she slowly started giggling, all while the electricity that had poured through her formed a tail right above her butt. A butt that was dramatically growing, as well as her chest and her general figure. All while she kept moaning and giggling, like she had just been cut loose from something that was supposed to be important. Oh well, being all sorts of curvy and busty and giggly was much more important, ehehehe...

It wasn't just her body that was changing either. The electricity combined with the ears that she wore was causing her outfit to shift. From a dress that was better fit for an idol to an incredibly generous kimono that showed off a little too much. Whether it was her cleavage, or the way it was parted down below and pushed out by her buttocks. She looked like an oriental bimbo, and she definitely liked it. Especially with how she bounced and giggled as her tail swayed left and right.

The more she changed, the more Tamamo felt something pouring into her. It was... It was everything that made Elizabeth such a good singer. Because she was a good singer, it's just that she had to focus when she wanted to sing at her best. And that knowledge was easy to access for her. Because it was pouring straight into her heart... No, into the Saint Graph that sustained her.

"Is this truly supposed to work in this fashion, Da Vinci!?" Tesla shouted, not out of fright or out of worry. But merely questioning it, since the way that Elizabeth had been turned into an oriental fox bimbo had been a little strange. Then again, he was the one that had been pumping the device full of energy, so...

"Not at all! But you've done a great job at kicking the machine into high gear, so why don't you lend my dear Tamamo a hand as well, Tesla?" Indeed, this wasn't in the specs. But that didn't mean it wasn't perfect. She needed Tamamo to be at her most intelligent. So what if she ended up sacrificing a clever mind? As long as Tamamo was at the peak of knowledge, nothing else mattered.

Tesla didn't get a chance to react beyond that as the machine sent a shocking feedback through him. Well, he should've seen this coming. But it wasn't like he could see much, not while he was being pumped full of... Whatever it was. He really didn't know what it was, it was definitely something, but it was like his brain was being sapped faster and faster and making it harder and harder to think.

The faster he was being drained, the faster his body was changing. Growing smaller and slimmer and wider in the best places. No need for big manly shoulders, he needed big fat breasts that would weigh down what little mind remained after it had been drained into the right fox. No need for muscles, he needed an extra thick derriere that would lure in every kind of partner because they could think for him. And he definitely didn't need that manhood, and extra slick and extra wet pussy would be more than enough considering how little he needed to think.

As soon as Tesla's own bimbo fox-tail formed, he had lost everything that made him male. And she already looked like she had been very used to the sense of femininity that was perfect for a genuine bimbo. She looked like she could be on the prowl in some sort of oriental district, barely able to get out so many kinds of complicated words. She knew what to say to get her way, and her body would do the rest. Anything else? Her partners would help her with. Whether it was what she wanted besides a nice dicking, or... Or... Gosh, she couldn't think of anything at all, could she..?

Tesla and Elizabeth both giggled, now looking like a pair of bimbo fox twins that looked just like mockeries of the genius fox that was currently absorbing all of their knowledge. And since they had been zapped to the point where nothing really remained in between their ears, nothing stopped them from looking at one another and giggling as they grabbed their hips and started kissing. Oh, it felt good to have their plush and plump lips press against one another. So much so that their legs locked between each other and started grinding...

As for Tamamo, she now understood everything that Tesla had ever obsessed over. Granted, she discarded everything that remained of his pride. She wasn't into a rivalry against somebody as thieving and conniving as Edison. No, everything that she knew was for her Husband. And she wouldn't want her to be at odds with a fellow Servant. As long as those other Servants wanted nothing to do with her Husband, then everything was going to be okay... And if they did try to get at her, well, now she absolutely understood how she could possibly sabotage them and add their knowledge to her own while leaving them unable to even get close to her Husband.

"Da Vinci, dear... My spectacles..." Tamamo gasped and panted, trembling all over as the rush of knowledge had left her painfully aroused. Good grief, her body was not used to this kind of sensation. But that didn't mean she detested it. Far from it. She would learn about it and use it to her advantage.

Her request was heard and answered, as Da Vinci handed her a set of fox-themed spectacles. "I made these specifically for you. For the single rival I would ever want for my intellect." Da Vinci chimed, all while weaving her fingers together with Tamamo's after she had slipped the spectacles onto her face. "You look as beautiful as anything I've ever painted... No, you look more beautiful than that, my dear Tamamo."

"Such an emotional appeal..." Tamamo chuckled, before she pushed her lips up against Da Vinci's. "But I suppose even a genius like you can't resist that kind of emotion. And neither can I, even after what you've helped me learn. So just this once, I will give you the kind of treatment that I reserve for my Husband. Savor it, Da Vinci. My fellow Genius."

Two geniuses let their passions reach all new heights, while the ones that had donated their knowledge continued to fuck like animals. And soon after, Chaldea would fear the newest genius and her devious schemes...

As she planned to reduce all possible rivals to the same stupefied level as the other volunteers, all so she could hoard it with her dear Husband and her dear Da Vinci...