[Cowgirl TF, Brain Drain]

Chaldea. A bastion for humanity’s fight to save their own history. And a hub where many individuals from across that history meet to try and fight for this common cause. Even if they would normally be trying to kill one another without even thinking.

Not everyone were able to get along despite this though. For some, their conflict was too storied to make them calm down. The hindu brothers Arjuna and Karna were one such pair, and there were many more like them. But some were more subdued with their hatred, as was the case for the Oni and their mortal enemy.

Raikou. The Oni-slaying contradiction. The woman who had just as much oni blood as the rest of them, yet used the strength that it gave her to fight against them. Because she had been contaminated by the humans that raised her.

And if there was one person that hated her more than anybody… It wasn’t her mortal enemy. No, Shuten Douji merely found her an annoying presence. One that she could ignore for the sake of further entertainment. But her companion, Ibaraki Douji?

That little banana-haired Oni wouldn’t stand for this! Why was that woman, who had slain her wonderful Shuten, walking around like nothing had happened?! Why was she mingling like she didn’t owe a blood debt to every single Oni in history for what she had done!?

Ibaraki didn’t like it. She also didn’t like how her Master had specifically told her to not touch that infernal woman. Because she knew what would happen if the two came to blows… And it would probably be the loss of the blonde Oni’s head. Wouldn’t be the first time that it happened after the two incarnated as Servants.

So, she had to take a different approach. One that would work no matter what. Because while Raikou was definitely a strong woman, one that had killed so many Oni in the past, her current state as a Berserker left her utterly vulnerable to certain people. Including young children, who she couldn’t resist at all. And it was that lacking resistance that spelled her out her downfall.

Ibaraki made her preparations. She stripped away most of her Oni features using a little bit of her own legend, when she disguised herself as an old woman to regain the hand that one of Raikou’s foul assistants had severed, leaving her looking like any common little girl. Even her hair wasn’t as strikingly blonde as usual, making it harder to notice who she was.

She looked at herself in the mirror and giggled a little. She kind of enjoyed the look. Maybe she should pull it out another time, especially when Shuten was near. Maybe she’d praise her for her smarts… Or she’d bully her for going through this much effort. It was hard to guess either way.

For now, she had a woman to trick and ruin…

---

“Oh my. Mama has a little visitor?”

Raikou spoke up as she looked down at the disguised Ibaraki standing outside her room. She had been polishing and sharpening her blades to make sure they were ready for another assignment, while also knitting a little gift for her Master. Which meant that her room looked… A bit strange, given the yarn rolling around on the floor, covering the blades that had been neatly laid to rest.

“M-Mmhm!” Ibaraki nodded. All while sweating underneath her disguise. It was one thing to hatch a master plan to mess with the woman that had humiliated her dear Shuten over and over and over… And it was another thing to be standing in front of her, trying to both suppress her embarrassment and her rage so she wouldn’t be found out. “I-I have a gift for you, m-miss Berserker!”

The maternal Berserker giggled at the young girl’s nervous appearance, kneeling down so the two could look straight into each others’ eyes. “Please. You can call me Mama. Everyone does.” She said with the brightest smile that she could muster. While resisting her own urge to cuddle the adorable young girl.

“M-Mama…” The Oni said as she let the word roll around on her tongue. She didn’t understand why, but it did sound really nice. But she couldn’t let it consume her. She had something she needed to do. “G-Gift for Mama, t-then!” She said, as she reached into the bag she was holding in her other hand, pulling out a rather expensive looking bottle of sake.

Raikou shook her head a little. “Sake? A little girl like you, buying sake?” She asked, and the young girl nodded with that same air of nervousness. “Hmmm… I suppose I’ll have to scold whoever sold you this, but…” She muttered, before slowly taking the bottle from the adorable youth and pecking her on the cheek. “The gesture is appreciated, dear.”

Ibaraki could feel her skin growing cold as she felt that kiss push against her cheek. She hated it. And yet she enjoyed it. But she hated it more so than anything else. Because she wasn’t supposed to be enjoying it! This was her mortal enemy!

“T-Thanks Mama!” She cried out with the fakest sincerity she could muster, as she slowly watched the older woman close the door. No doubt to try and spare the girl the view of her indulging in her brand new alcohol. “W-Wait, Mama!”

Raikou raised her eyebrow, as she looked towards the younger girl. “Oh, you want to…” She paused, giggling a little as she opened the door fully. “I suppose that you’re allowed to see Mama drink, since you went through the trouble of getting her this.”

Ibaraki trudged over the yarn on the floor as she took a seat on the older woman’s bed, watching her as she walked over and grabbed a small glass from her drawer. The kind that she kept hidden from everyone’s prying eyes. Because there were times when even she, the maternal maniac that she had become, needed to indulge. Which was exactly what the disguised Oni had planned for.

“To you, my little sweetheart.” The bodysuited Berserker said as she poured enough sake to fill the glass right until surface tension kept it from spilling, before downing it all without taking a moment to consider whether or not she had been tricked. That was her weakness. Trusting children when she should know better.

And the ill effects of the sake immediately kicked in, as she was forced to drop the glass as a warmth started to pour through her. A warm that left her wholly ignorant of the world around her, as her head started to pulsate…

“What’s the matter, Mama?” Ibaraki said, her disguise tearing itself away as she revealed herself in all of her horned and cocky glory. “Feeling a bit sick? Under the weather? About to tear yourself apart because you’ve been fooled by the great Ibaraki Douji?” She was way too happy with this turn of events, the way she grinned from ear to ear only emphasizing her joy.

“Ibaraki..!” Raikou shouted, the presence of the Oni breaking her from her haze for a moment. But only a moment, as her attempts to draw her blade resulted in her arms brushing against her breasts. Her melons. Her… Her udders.

They bounced. They squirmed. They throbbed. They ached. They needed release, as that warmth from earlier started to spread through them. The warmth that was making it harder and harder to think….

Ibaraki grinned as she reached towards the sake, casually waving it in front of the older woman’s face. “You really fell for this! This really simple trick! You didn’t even think to check if I was disguised, and you downed this great Ushi-Oni Sake like it was nothing! You utter fool! I can’t believe my Shuten lost to you, when you’re this much of a fool!”

Ushi-Oni. That was the name of the Oni identity belonging to Raikou. But if you dug beyond that, you’d know that it was the name of certain cow-flavored Oni. Known for their huge assets, they were easily milked. Though nobody dared drink their ‘milk’, because it had the greatest flavor of any sake known to Man or Oni… It was cursed.

The one who drank it would fill their ranks. Another cow would join them, with their breasts making just as much of this ‘sake’ as the one who had been milked to make the first dose. And though these Oni had practically died out as a result of Raikou’s efforts… That didn’t mean that their ‘milk’ had disappeared. Far from it.

Raikou let out a powerful moan as she felt her nipples squirting. She could feel the horribly scented liquid running down her body. But she didn’t care. All that she cared about was the warmth inside her, and how it was driving her mad…

She got down on all fours, as the warmth concentrated in her leaky tits. With her body taking up less space, it would spread to more parts of her… Which was exactly what the sake wanted.

Another moan left the older woman’s lips as her thoughts were being churned into more fuel for her breasts. Her memories. Her strength. Her hatred towards Oni. Her love towards children. All of it melted away into nothing but milk.

Raikou moaned and moaned, with every moan turning into a moo after being dragged out. All while the liquid had started to leak through her bodysuit, making a useless puddle on the ground below her.

Ibaraki laughed as she watched the woman transform before her eyes. Breasts growing heavier. Body growing thicker. But most importantly, her name was becoming far too literal. Ushi-Oni? A name that struck fear into fellow Oni considering what she had done thanks to the humans contaminating her inner self?

She was little more than a Cow Oni now! With horns poking out the side of her head, and a cute tail swishing back and forth! Even her outfit had been affected by the power of the sake, turning a humiliating white with black spots. She really was little more than a cow like this. A cow meant to be milked, even if her milk was toxic to most people…

Ahhh… This called for a celebration! And wouldn’t you know it, she had some alcohol right here! The perfect thing to chug in a moment of victory!

Ibaraki didn’t even pause to think about her actions as she downed a big mouthful of the Ushi-Oni sake, only realizing that she had screwed up completely as she felt that overwhelming warmth within her. And unlike her target, she had little defenses to speak of.

The banana-haired Oni cried out as her horns grew thicker, and a nice bovine tail grew from right above her buttocks. Her precious banana-flavored hair turned white and spotted just like the suit that the oni-blooded killer wore, since the Oni’s outfit was hardly her most characterizing element.

Changing her looks was far from the only thing the sake did. Especially for a girl with such small breasts as hers. She could feel the warmth spreading to her chest, intensifying until..!

Ibaraki let out a climatic scream as her udders burst out, explosively growing to the same size as Raikou’s as white-colored alcohol dribbled forth from her breasts. The ‘milk’ of a Cow Oni. The milk that had ruined her and her mortal enemy.

Raikou didn’t even pay attention to her enemy’s fall. In fact, she was too horny to notice anything around her. She just absentmindedly mooed, begging for somebody to milk her…

A routine that the former banana-haired Cow Oni joined in on, mooing and swaying her massive ‘milk’ filled breasts from left to right. She wanted somebody to milk her… Nothing else mattered to her. She wanted to be milked… She craved it, beyond anything else.

Luckily for both girls, they’d get exactly what they desired, as a certain purple-haired Oni walked into their room…

And neither of them would live it down, once they regained their minds. But it’s said that they became closer after their mutual humiliation. If only because they were now of the same blood.

Even if it resulted in the two slipping back into their cow-like mindset here and there...