[Brain Fuck]

The Servants that served Chaldea were a varied bunch. Most of them were heroic figures that wanted to help the humans of the present accomplish their mission. Which meant that they’d do anything that they could to save the flow of time. But a good few of them were more self centered, evident by the way that they were constantly up to no good.

If somebody asked all the Servants in Chaldea who they thought was the most troublesome and annoying Servant… They’d probably say Elizabeth Bathory. But once you added ‘intentionally malicious’, they’d point their fingers at the AI known as BB.

BB was… Well, describing her in one word would be difficult. She was a complex kind of girl for sure, considering that for all the times she had caused trouble, and those incidents numbered in the triple digits, she had been such a massive help in the few instances where she actually put aside her natural mischievous personality and joined forces with the other Servants. It meant that the Master originally cut her a lot of slack, despite everything she had done.

Unfortunately, one man’s patience only lasts so long. Even if she did everything to extend it. She spoiled him senseless whenever it seemed like he’d get mad. Especially with those fat tits of hers. Oh, he could never resist them, even if he desperately wanted to.

But even the greatest titfucks in the world couldn’t stop him. Not for long. Even as she merged with another Goddess to become a tanned beauty, the same form that she had used to trap him in a temporal loop, her sex appeal could only get her so far. And when she finally messed up the last time…

It was time to teach her a lesson. And there was only one way he could think of fixing her.

Breaking her Brain.

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“Ehehehehe… What’s up, Master? Why’d you want me to join you in your bedroom?”

BB, still taking on the rather exotic Summer look, giggled as she skipped into his room. Her bra was so dangerously tight that the only thing keeping the string that held her bikini top together from snapping was a single deep breath. She knew that, it was something she had arranged for, knowing that the Master loved tits above all else. And if he loved tits, he couldn’t lift a finger to stop her from causing trouble.

Her Master was not as happy. Especially as he glared straight into her eyes. “You know why you’re here, BB. And don’t think you can seduce me this time.” The black-haired young man said. Judging by his pants seeming fresh… He had already made sure he wouldn’t be forced to cum his sensibilities out so she’d get off the hook.

“Nooooo, I don’t think I dooooo.” The tanned beauty giggled as she got closer to that bed, ignoring his iron-willed stare. “But it can wait, can’t it? I’ve been aching so much, my breasts are killing meee… Can’t you give them a nice massage, Master?”

He didn’t budge. Not this time. “Why do you keep causing trouble, BB?” He asked. His gaze didn’t drift down towards her breasts. Not even a single time. He wasn’t going to let her wriggle her way out of it this time.

“You reaaaaally have to be a stick in the mud this time, huh, Master?” BB sighed, leaning up against the youth as she rested her head on his shoulder. “It’s in my nature, Master. I can’t sit still if I don’t see a bit of chaos happening. And besides, I know I’m the only one you really need. Who else could satisfy you?”

She seemed genuine as she spoke. Which just made those words sound even worse. Why would she genuinely believe something like this? “Are you really that selfish, BB? Do you have nobody else you care for, nobody else you give a damn about?” He asked. His hand clenched tight. He wanted to believe that she could be better. He wanted to believe that she wasn’t an egotist that was running wild inside his home.

“Nope! Nobody. Just me, myself, and I. And Master, of course!” The purple-haired gyaru chimed. She didn’t even hesitate. She didn’t even take a moment to consider that people might actually be hurt by what she did. She really was that self-centered.

The Master took a deep breath. This was all that he needed to hear. He really did need to break her. “BB. I’m afraid I’m going to have to fix you. Permanently.” He said, standing up as he turned towards her.

“Fix me? Ohohoho, you think you can do anything against me, Master? Do you really want to fight a girl that has so much power at her fingertips?” BB giggled. She didn’t take him seriously. She never did. Part of why she thought she’d be able to get away with this kind of behavior…

Which was why the thought of him using his Command Seals against her didn’t even cross her mind, evident by the complete look of shock in her eyes as the Seals started to flare up on the back of his hand.

“By the power of the Command Seal. BB. Sit still.” Her Master said, one of the seals burning up. It would be back in time, and it was nowhere near as strong as a proper Command Seal applied during a proper Grail War, but it would do the trick.

The tanned Servant let out a nervous giggle. “W-Well, Master, I’m glad that you know how to take charge, but aren’t you getting a little ahead of yourself? Don’t you think you might be going a little overboard? You could’ve just told one of the others to punish me, you don’t need to use those!” She tried to beg for her life. She knew that if he did something extreme, she’d probably end up with her Saint Graph irrevocably changed. Something that… She would rather perform on one of the others. For it to happen to her? Now that was just terrible.

“I’ve waited long enough. You’ve clearly shown that you don’t have any compassion for your kin, and you want nothing more than to spread chaos. The few times you’ve helped clean up your messes don’t even come close to the amount of times you’ve caused them. And you show no sign of remorse or repentance. By all accounts, I should’ve done this a long time ago.” Her Master explained, as he slowly unzipped his pants.

His cock, painfully erect thanks to the thought of what he was about to do, flopped onto the gyaru’s face, giving her a taste of what was to come. The scent. The shape. The taste. All of it soaked into her, as she couldn’t do anything against it. “W-Well, if you just want to fuck me senseless, that’s fine! You could’ve said that from the start! Don’t worry, I haven’t fucked anybody since the last time I serviced you! I just practiced to make sure that I fit you!”

“I’m not going to fuck you for pleasure, BB.” He explained as he climbed onto the bed once more, this time standing straight on the mattress as his cock slid across her face and pushed up against her ear. The perfect place for it to rest.

Her mind quickly caught up with his intent. He wasn’t about to do that, was he? He knew what the risks were! Nobody had managed to come back from that, not even the most divine Goddesses could handle that.

“M-Master, if you just take a moment and breathe, maybe we can come to an understanding! I promise to never cause any trouble ever again! I promise to help everyone with their problems, and I promise not to confiscate your pornography stash so I can change myself to fit your needs!” She tried to beg. She knew what was at stake. And as she begged, her lips ended up a bit too loose.

He twitched. “Is that why you went through all that trouble just to be a gyaru? Because you knew they were one of my favorite kinds of women?” He asked, and the purple-haired girl quickly nodded, hoping that it would mean that he wouldn’t fuck her ear. “I really should’ve done this the moment we met. Because of you, I never got those good books back. Because of you..!”

“W-Wait, Master, Don’t-”

BB didn’t get to finish that sentence. The sharp sense of pleasure flooding through her mind due to the cock shoving into her ear overpowered her thoughts and left her absolutely speechless, her jaw hanging low as everything came to a screeching halt.

This was why he made her unable to move. With her being paralyzed, it was easy for him to use her ear as a makeshift pussy. And the benefit of doing so was that he would thoroughly scramble her brain. That was just the effect that came with the thrusting. What came next was going to make the experience even more worth it.

“How’s that? How’s THAT? THIS IS HOW IT FEELS TO BE TAKEN ADVANTAGE OF, BB!” The Master shouted as he thrust in and out of her ear-pussy, slamfucking it as hard as he possibly could. Only his position prevented him from going faster, as it was hard getting a proper grip with his feet on the mattress.

But even with this speed, he could see her eyes rolling into the back of her head. He could see her drool running down her chin, representing her thoughts completely draining from that empty pink bean she called a brain…

Even though she didn’t say a thing, because her brain was currently too troubled to let any thought reach fruition, he didn’t care. He was too frustrated to stop. He just kept on thrusting, harder and harder until it felt like he was actually pounding against the brain itself.

She kept on drooling and moaning idly, the noises little more than filler because she couldn’t do anything else. It felt too good to have her brain fucked like this. It was why she had heard so much about it being the proverbial achilles’ heel for any woman. All it took was a cock inside the ear, and they were turned into nothing more than cumdumps that could do nothing except for accept all of the cum that their owners poured into and onto them.

And that was exactly what her Master used her for. Nothing more than a hole to fill. The softer that ear got, the harder he thrust. Because he wanted to make sure that she was thoroughly broken. That was what he had set out to do, and if he failed… Then she’d just start all over.

The Master got closer and closer to his climax, his grip on the gyaru’s head tightening as he practically dug his fingers into her skull. “Take it all, BB! TAKE IT, SO YOUR BRAIN BREAKS!” He shouted, gritting his teeth as he shoved his cock as far in as it could go, before the rush of seed poured out of the tip of his rod.

BB let out a scream in time with her Master’s own. Though hers was deprived of deeper emotion. It was more just a primal cry of pleasure, as her brain got absolutely smothered in sticky white juice that quickly soaked into it. The virile seed that was supposed to impregnate somebody now wriggled inside of her mind, pulling it further and further apart. There was no chance of her ever recovering from this, once they took hole and altered her on a fundamental level.

“There. Finally.” The young Master said as he pulled his cock out of her ear, panting a little as he saw just how wet it was. He could definitely see a few bits of pink mixed in with that wet stuff… No doubt a result of her mind being absolutely destroyed. Leaving her brain little more than a liquid mess on his rod…

But… Even as she collapsed against the bed, her brain completely turned to mush as it drooled out of her ear… Was he really done with her? How could he guarantee that she wouldn’t cause problems again? How could he make sure that if she somehow got returned to normal, she wouldn’t go straight to him and take her revenge?

He did have two Command Seals remaining. Both of them brimming with power. If there was any time to use them, it’d be right now. “BB. Listen.”

The girl with the Broken Brain sat up, listening to her Master even if there was no brain home inside her head. She just stared straight at him, her eyes empty as she smiled like the idiot she now was. She existed to do nothing except take another cock or three…

“By the power of my Command Seal. You will never lose your need for cocks. Ever. Even with your brain broken, even with your spirit rewritten, the permanent truth is that you are a complete slut for cocks. You want them draped on you. You want them filling your holes. You want them to completely destroy you. And only then, will you be satisfied. For little more than a minute, before you crave them once again. That is you. That is who you are, BB.”

His words sank into her brain, cobbling together the watery mess inside her head as her eyes slowly started to fill in with color once more. This time, her irises took on a much needier shape instead of the sharp and smug look they had previously. After all, she was little more than a cock slut. She needed to demonstrate that she was absolutely obsessed, as her irises became throbbing hearts.

“Cock! Cock! Give me cock!” BB cried out as she snapped back to consciousness, practically smacking her face into the young Master’s rod, gasping and panting as she slobbered all over it. A far cry from the tease she had once been. “Gimme gimme gimme!”

Her Master grabbed ahold of her head, pulling her away from his cock. “Remember. This is what you’re working for. This cock. Nothing else in the world matters to you. Got it?” He gave her another command, as his scent made sure that it all sank in. That way, she’d understand what it meant to her…

“Yes! Master’s cock! Master’s wonderful big hard shaft that should be fucking me right now!” The brain-broken girl cried out. Her brain was too broken to dwell on the particulars, when she really just wanted cock at this point. Maybe the Command Seal had been too effective? No matter, it meant that he had a way to control her.

He smiled. Despite this lust, he still felt that there was something missing. As he held his hand aloft, the last seal started to glow. “By the power of the Command Seal, you will do anything I ask you to. There’s nothing that satisfies you more than doing what I tell you to, and the cock that you receive as a reward. That is the fundamentals that make up your existence, BB. Engrave it in your soul!”

“Yes! Yes! I’ll do anything! I’ll do whatever you tell me to! Just give me cock! Give it! Give it give it give it!” The broken slut cried out again and again, her tongue hanging out of her mouth in such a needy fashion. She just wanted to suck, she wanted to blow, she wanted to satisfy her Master in any way that he asked her to. Because he had made that a part of her Saint Graph. This desire would never go away, it would never be permanently quenched.

By fucking her brain, by dumping his seed into her head, by making her dependant on him using his seals, her very existence was now irrevocably changed. Any time somebody else would try to summon her, she would disregard them and quickly try to find him. Because She needed his cock. She needed it to live. Without it, she’d end up with her mind drooling out of her ears as she kept on begging for him to play with her.

“That’s what I wanted to hear.” The Master said with a smile. This time, he was sure that she wouldn’t find a way to get back at him. And so, he pushed his cock up against her lips. “Now suck.”

His command reached her brain, and BB immediately wrapped her mouth around his cock. She let that tongue slide all across his shaft, forcing it as far into her mouth as she possibly could. She sucked all of the dirty stuff off it as she took it all the way into her throat, the thing bulging out as it filled her. She didn’t care that it would normally give her some sort of discomfort. She wanted it beyond anything else…

The Slut grabbed ahold of her Master’s hips as she forced herself to gyrate back and forth. Master didn’t need to thrust because he had given her a command, and she was going to fulfill it. She sucked and sucked, while simultaneously facefucking herself using this back and forth movement. She didn’t care that she could feel it smashing deeper and deeper. She craved it too much to stop.

He grinned as he watched her suck him off with such an intense look in her eyes. A far cry from the trickster she had been. Now that she was utterly devoted, nothing was ever going to go wrong again. Life in Chaldea would be peaceful, and if anybody wanted to punish her, he’d just command her to play with them for a little while.

But… There were other troublemakers besides her, weren’t there? And they were just as terrible as she was…

Maybe he should break their brains too, with his Brain Broken Slut’s help...