Ch 147: A challenge.

Akeno was grateful for the light compulsion causing the streets to be deserted at night as they reached Rin's home. Anyone seeing Darkness being led on a leash would have called the cops on them.

Scathach had joined them mid-way, raised an eyebrow at the sight of Darkness, but had not made any comment, only introducing herself to Jeanne, Melusine, Medb and Darkness.

Akeno smiled with satisfaction as Rin opened the door of her residence, and they entered inside. So far, the Holy Grail War was going very well. She had secured the help of four of her six rivals, as well as one local Master, guaranteeing that she wouldn't be outnumbered later on, and solved Sakura's issue. She needed to make preparations against Gilgamesh and Kiritsugu Emiya, which, in both cases, translated into reinforcing her allies.

"We're back, Sakura!" called out Rin as they removed their shoes.

"Welcome back, everyone." politely said Sakura as she came out of the living room, warily observing the newcomers. Her eyes widened as she spotted Darkness's new accessory.

"Ah, Sakura, those are Ruler Jeanne and Ruler Melusine, who have been sent by the Counter-Force to monitor the Holy Grail War. Jeanne, Melusine, this is my sister Sakura."

"Pleased to meet you." smiled Jeanne with a polite nod. Melusine only nodded.

"I-It is nice to m-meet you, too." stammered Sakura, doing her best to hide her alarm.

"And those are Rider Medb, and her masochist of a Master, Darkness. Please stay away from that pervert, she might infect you."

"I'm not a pervert!" replied the pervert, with a perverted smile she couldn't suppress. "I have been taken captive! But you will never make me submit to you!"

Sakura unconsciously made a step back, her face frozen stiff.

"Yeah." sighed Akeno, who had just finished removing her boots. "I'm going to take Darkness away, before she makes an even worse first impression. Medb, please follow me. Britomart, would you mind guarding the house?"

"Understood" nodded Britomart, dematerializing.

"Please do." nodded Rin, not wanting to look at Darkness any longer. "Sakura, there's also one more Master, a boy, and Berserker. They're currently patrolling with Chisato, Asuka and their servants, and they will be back before morning."

"Tohsaka-senpai, at this rate, we'll soon run out of empty rooms." remarqued Sakura.

Akeno didn't hear Rin's answer as she dragged Darkness to her own room, Medb following closely behind.

"Will you remove that damn collar now? I'm not going to attack you." demanded Medb as Akeno closed the door behind them.

"I wonder…" said Akeno as she started pouring mana into the Sanctuary. "Darkness and the other Masters share an understanding. We know that once defeated, we won't rebel against the victor, because the Gods are watching, and they will punish us if we don't follow their rules. But you, however, weren't present at the time, and you aren't bound by those rules. And between Darkness and you, you were the one making the decisions, am I correct?"

"Of course! Darkness is fit to be ruled, not to rule, and certainly not to rule over this Queen." said Medb with obvious pride.

"I think so, too." smiled Akeno, ignoring Darkness's retort. "And I'm starting to understand why she was gagged earlier. But do you think that I should be ruled by you, or rule over you, Medb?"

"Isn't that obvious?" immediately replied Medb. "I can tell we have similar dispositions, but I am a Queen, and am likely much more experienced than you. You will kneel at my feet, Akeno, and I will favor you and make you my right hand, provided that you become an obedient pet. And I'll have Darkness transfer the Command Spells over to you. You will provide me with more mana than my current… Master." Medb said the last word with scorn.

"Haha, this is too much…" panted Darkness as her knees gave way, and she fell on all fours.

Akeno patted her head.

"How cruel, Darkness, to be rejected even by the Servant you summoned." she said softly.

"Medb, I am not going to accept this transfer. Fate has bound you to her, and I think she still has her role to play. So you will have to tolerate her antics for the foreseeable future. I will, however, make Darkness much stronger than she currently is, so she will supply you with significantly more mana during battle."

"…How will you do it?" asked Medb, frowning. She couldn't think of any magecraft that would allow a Magus to quickly grow in strength, unless it was about draining mana from a lot of people. But she didn't think this was the method Akeno intended to use.

Once Sanctuary was filled with enough mana to last for a little over five hours outside, and five days inside, Akeno set it on the desk and teleported herself, as well as Darkness and Medb inside. They appeared in the house's living room.

"A reality marble? That is what this mystic code is for?" asked Medb as she looked around.

"That is correct." nodded Akeno. "But this one is a bit special. Time can be set to flow faster inside it, so we can spend a few days, just the three of us, before we would need to join with the others and go to school."

"I want that mystic code!" demanded Medb, already imagining the possibilities.

"Medb, what do you think of Britomart's performance tonight?" asked Akeno, dropping the chain leash and starting to remove the school uniform Darkness was wearing.

Darkness's warped smile returned.

"She is very strong and fast. To an extent I found abnormal, even for a Servant. Is it because you supplied her with a lot of mana?"

"That is one reason." nodded Akeno, removing Darkness's shirt. Darkness was now down to her white underwear. "Considering my nature as a half-fallen angel, half devil, and the gifts I received when crossing over to that timeline… I have a mana capacity that must be well over fifty times that of your average person, and peak grade Mana Circuits. That had some influence. But the biggest factor in her abnormal power is that I gave her a special kind of training. One that Darkness and you are about to receive. You will submit to me, and you will love it."

"Never!" claimed Darkness with a huge grin.

"How about a bet?" slyly asked Medb.

"What do you propose?" asked Akeno with a small smile, completely stripping Darkness of everything save the collar. She took handcuffs from her inventory. The blonde girl gasped as Akeno cuffed her hands behind her back.

"Be my slave for three, no, five days. If I haven't convinced you to permanently become my slave by the end of it, I will let you dominate me for five days as well."

Akeno snorted.

"Oh? You want us to compete to see who is the better dominant? You do realize that with your powers sealed, I can already do whatever I want with you, right?"

"Maybe." acknowledged Medb, smiling. "But you will pick up the glove, right? Your pride as a dominant will not allow any different outcome."

"Maybe. I like the idea. But as the challenged party, I get the first turn, and the right to decide on the particulars. And I will make a contract about it."

Akeno used her limited access to Noah's soul magic to make a contract.

SOUL CONTRACT

Queen Medb, Heroic Spirit, hereby referred to as Medb, declare being willing to accept Akeno Himejima, hereby referred to as Akeno, as her dominant and trainer, for a period of thirty days in the real world.

During that time, Medb will not attempt to rebel against Akeno or use a third party to interfere with her training.

After those thirty days, if Medb is unwilling to submit to Akeno in all ways, Akeno will accept Medb as her dominant and trainer for the same duration, under the same conditions. Medb will be allowed to use the Sanctuary to the same extend Akeno previously did.

This cycle can be repeated upon mutual agreement.

Signed.

"Why thirty days?" asked Medb as she read the terms.

"I could do it quicker, if I were to use a few special magic items, but your challenge has me fired up. I want to train you the old-fashioned way. Are you scared?" grinned Akeno, appealing to Medb's pride.

"Scared? Me? Thirty days it is. But when it is my turn, I will pay you back for everything you'll do to me. Do you have a feather and ink?"

"This contract is to be signed with a drop of blood." smiled Akeno, creating a small dagger made of hardened light. Without hesitation, Medb nicked a finger on it and pressed it on the contract. Akeno did the same, and the contract disappeared in a burst of flames.

Akeno removed Medb's collar.

"You made a huge mistake, Akeno." grinned Medb. "I am a Queen through and through. No matter what you do to me, I will not submit to you, and then, it will really enjoy my time with you."

"I so love a challenge, Medb." snorted Akeno, taking Darkness's leash again. "No follow me, both of you."

She led them to the basement. A square room with red walls, thirty meters to the side, with red walls. It was larger than the house above it. Many closets and wardrobes and shelves held a huge variety of items.

"Ah… Ah…" panted Darkness, her eyes darting from one piece of furniture to the next.

"An interesting place." nodded Medb, starting to explore the room. "I can see many thinks I'd want to use on you and Darkness."

As Medb looked around curiously, Akeno forced Darkness to stand between two wide sheets to black latex.

"W-What is this?" asked Darkness excitedly.

"Something you are going to like, slave. smiled Akeno as she bound Darkness's ankles wide apart to the inner leather straps of the contraption. Removing Darkness's handcuffs, she did the same with her wrists, securing her hands up on each side of her head.

The contraption was imbued with Noah's self-sizing magic, and the bulbous rubber piece attached to the front sheet adjusted itself to be level with Darkness's mouth.

Medb walked closer and watched curiously. She had never seen a piece of furniture like this before.

"Open your mouth, slave." commanded Akeno, and Darkness obeyed. It took a bit of force to push the mouthpiece where it belonged, and Darkness moaned as she stared at Akeno in anticipation.

"That gag is hollow, slave." smiled Akeno. "That will be the only way you'll be getting air for a while.

She took the airtight slider on the side and started closing the two black latex sheets around Darkness. When she was done, she pressed a button near the bottom of the device, and the soft hiss of air being expelled was heard.

"What is this strange thing?" asked Medb.

"This is called a vacuum bed. This one is a vertical model. I would explain how it works, but I'm sure you can guess just from seeing it."

As the air was expulsed from between the sheets, the latex started molding itself around Darkness's figure, and Medb stared at her increasingly defined shape, fascinated. When Darkness occupant was properly vacuum-packed, the pump turned itself off.

"That's very interesting. She can't see or hear us?"

"She can't see. She can probably hear, but sounds will be muffled. And she can certainly feel." grinned Akeno as she gently squeezed Darkness's left breast. The girl held captive by the latex squirmed and moaned with renewed vigor.

Using several pieces of adhesive tape, Akeno placed two pill vibrators against Akeno's nipples, and two stronger ones against her crotch, on both the front and rear sheets. She activated them all to function at random interval and intensity. Darkness moans and squirming intensified.

Medb was watching with a smile, thinking that the modern era had some interesting tools, when Akeno cleared her throat.

"And now, my other slave, it is your turn."

…

Medb tried hard to not move a single muscle. A task she found very difficult, considering how simple it sounded.

"I love being a plaything."

Her own voice, transmitted by the device pressing on her ears, distracted her from her train of thoughts. As if the vibrator making only the smallest of contacts with her crotch wasn't enough.

She had to admit that Akeno was much more devious than she had expected. Following the rules of the contract they had just signed, Medb hadn't tried to resist when Akeno had undressed her, setting her red leather outfit aside. And she had cooperated when Akeno had asked her to repeat a series of sentences like this one, holding her smartphone near her mouth.

When Akeno was satisfied, she had stretched over Medb's head a black hood made from the same material that Darkness was getting thoroughly acquainted with, with holes only for her nostrils, cutting off her vision and forcing her mouth closed. She had felt Akeno guide her toward one of the larger pieces of furniture she had seen earlier, a sturdy X-shaped wooden cross padded with leather, with another part added to the center to support the back and head of the individual who would be bound to it. Pressing her back to it, Akeno had used many straps to tightly secure Medb to the cross. There was even a strap on her forehead that kept her head pressed against the leather-padded headrest.

Then, Akeno had added something pressing to the sides of her hooded head, over her ears. Medb didn't know what it was, but she couldn't dislodge it.

And the whole cross rotated, becoming horizontal.

Medb could still squirm a little, with her limbs having a few centimeters of leeway, and her hips and torso were relatively free of bonds.

For a few minutes, nothing happened. Medb had wondered if, maybe, Akeno had gone to play with Darkness, when she felt something touch her lower lips. The contact was very light, barely touching her, but it vibrated, sending her some pleasant sensations. Medb managed to ignore it for a while, but it was maddening, and before she knew it, she lifted her hips to press her crotch against whatever it was.

And as she did, she touched something else, and received an electric shock!

Medb understood. The vibrator would make her horny and distracted, and would be impossible to ignore, but if she moved her hips significantly in any direction, she would receive a shock.

That was devious, and Medb promised herself that she would make Akeno experience this torment as well. But she would reduce the allowed range of movements to nearly nothing!

And then, she started hearing her own voice.

"I am born to serve."

"I wish to make Mistress happy."

"Mistress, please take away all my senses and torment me a lot."

"I feel calm when I am bound."

"Helplessness is happiness."

"My place is at Mistress's feet."

"I am a horny slut. I need something to fill my holes."

"I want to be a bondage slave forever."

Again and again, she heard those sentences, and many more of the same kind. There was always at least thirty seconds between each of them, and the interval was random enough that her voice always caught her by surprise, making her wonder for a moment if the words came from the device on her head, or if they were her own thoughts. Medb, in normal circumstances, would easily be able to tell the difference, but now, deprived of some of her senses and in a severe state of arousal robbing her of her focus, the difference between the two was starting to blur.

And if all that wasn't enough, Medb occasionally felt Akeno's hands on her breasts, armpits, stomach, crotch and thighs, gently rubbing, kneading, fondling. Her touch felt very good, too, but that only made the torment worse!

After what felt like hours of this sweet torture, doubt started sprouting in Medb's heart. Her confidence that she could take anything Akeno would throw at her, until her turn came, started to crack.

…

As Medb was stewing nicely, Akeno decided to give Darkness a taste of something different. She had, after all, promised her a whipping. Pressing the button to let air between the layers of latex, Akeno moved the slider to break the seal between the sheets, and a rush of cold air made Darkness shiver. She had been sweating a lot, as shown by the inner layers.

"I do not think I need to ask if you liked this." grinned Akeno as the removed the mouthpiece from Darkness's mouth and started untying her.

One look at Darkness's face was enough of an answer.

Once Darkness was free, Akeno took from her inventory a white towel.

"Wipe out your sweat, Darkness. I'm in the mood for some rope bondage."

Darkness's goofy smile returned, but she froze when she saw Medb's form lying on the wooden cross.

"How many times did you come, slave?" smiled Akeno. She was pretty sure Darkness had gotten at least four orgasms.

"You brute, subjecting me to this d-decadent torture! I will not submit to you!" retorted Darkness, almost quivering with pleasure.

"Yes, yes." said Akeno, rolling her eyes. She found Darkness's bravado cute, but if she didn't vary her retorts a little more, she was going to fetch a gag. "But we both know that you loved the experience. Being held helpless by the tight embrace of the latex, deprived of your vision and freedom, being stimulated mercilessly, not knowing when and where your Mistress with touch your body…"

"Aww." moaned Darkness as she hugged herself, legs tightly pressed against each other.

"Quickly dry your body so we can start the next round of your training." said Akeno, taking several bundles of red rope from hooks on the walls.

Darkness didn't need to be told twice and used the towel. Akeno got to work with the ropes.

A few minutes later, Darkness was well and truly trussed up, with a tortoise shell pattern around her torso and waist, her wrists bound above her head to the ceiling, and her legs spread wide apart. Despite the recent wiping, Darkness's love juices were once again starting to run down her thighs.

Akeno came back in front of Darkness, presenting a penis gag to her, and Darkness opened her mouth without waiting to be ordered. Akeno fastened the gag tightly, then took from one of the walls the worst instrument of the room. A short whip. It was only a meter long and fairly thick to distribute the force of the impact on a larger surface, but it would still sting.

Akeno smiled as she took position behind Darkness, and swung it with a swooshing sound.

"Mmph!" moaned Darkness, her body jumping a little.

Akeno fell into a rhythm, giving Darkness a few seconds to recover between each strike, and her moaning lustfully into her gag. She slowly increased the strength of the blows, studying Darkness's reactions for any sign that it might be too much.

But one thing was certain, Darkness was a hardcore masochist. By the hundredth strike, she has orgasmed twice, her body spasming in her bonds. Akeno chuckled as she put the whip back on the wall and chose a flog. It wouldn't be as painful as the whip had been, but Darkness's ass was now a healthy pink, making her skin sensitive, and the flog didn't risk causing injuries to more sensitive parts of her body. Like her breasts.

Darkness had her head lowered as she panted, and Akeno took hold of her ponytail, forcing her head upward. As she had expected, she found Darkness's eyes seemingly melting in ecstasy.

Akeno kissed her gag as she rubbed the handle of the flog between Darkness's legs.

She then took two steps back and gave Darkness's chest a good flogging, grinning as Darkness's large breasts seemed to dance with each blow. Darkness moaned again with each strike, and experienced yet another orgasm.

Satisfied, Akeno put the flog back on the wall, and took Corruption from her inventory. Darkness's eyes widened as she stared in fascination at the large dildo she guessed was about to take her virginity.

Once she was done putting it on, Akeno untied the rope around Darkness's ankles and wrists, only to rebind her hands behind her back.

"Come here, slave. It's time for you to be used like the fuck toy you are." smiled Akeno as she put a finger through the D-ring in front of Darkness's collar, leading her toward the bed on one side of the room.

Darkness moved on trembling legs, moaning as even she was starting to feel exhausted after experiencing so many orgasms in a short time. She climbed on the bed, following Akeno's guidance, and Akeno placed her on her knees, bent forward with her forehead pressing on the mattress.

Akeno positioned herself behind her captive to take her doggy-style. Keeping one hand on the rope binding her wrists for support, Akeno lined up with Darkness's sopping wet pussy, and proceeded to fuck Darkness senseless.

…

An hour later, Darkness woke up, feeling warm and comforted. She felt disoriented for a moment, before the memories rushed back.

"Did you sleep well?" asked Akeno with a smile, her face only a few dozen centimeters from Darkness's.

The blonde girl realized where the feeling of warmth came from. She was still bound by the red rope, and Akeno was hugging her like a body pillow.

"Yes." said Darkness with a blush.

"Good. What did you think of your whipping? Was it too intense? Not enough? I want an honest answer, Darkness. Not your usual crap about never submitting. You do not have to keep up appearances with me."

"… It was, just right, toward the end." replied Darkness, her blush increasing.

"I'll keep that in mind for the rest of your training. Is there anything else with what I have done to you, that you aren't satisfied with?"

"… You have taken my virginity."

"Yes."

"… You have to take responsibility."

"Of course. You belong to me and the Champion I serve. We will never throw you away or abandon you."

Darkness slowly exhaled and felt herself relax.

"Tell me, Darkness. About your encounter with this guy Marcus, and how he treated you." softly said Akeno.

"…He joined our group as an adventurer. He wasn't strong back then, but he got along well with Kazuma, and he improved at a quick pace. Well, I do not think you want every single detail, but Marcus proved to be dependable. He saved us from many troublesome matters, and eventually married Iris Stylish-Sword Belzerg, the first princess. After the wedding, he became somewhat distant with our group. He didn't participate in missions anymore. Before we really realized, we hadn't seen each other for months."

"And then, suddenly, I was transported to another world by Loki-sama. Marcus was there, with a few men and women I have never met. Marcus told me that, in that world, he and his group were fighting monsters called Vampires, similar to the one Artemis-sama showed us before we chose our catalysts. He had been given a mission to prepare eight people for acting on his behalf, and that he brought me over to make up for the number, but that he didn't expect anything from me."

"He called me hopeless, so he didn't bother doing anything to help me become stronger. He only had me stay in a safe city, giving me money to live, and he told me that after the candidate was selected, very likely one of the other seven, he would bring me back to my world."

Akeno nodded. From what Darkness had just told her, she wondered of Darkness's selection was truly random. Maybe Loki had taken pity on her, and decided she would have a better life of part of Noah's harem.

"He didn't have any romantic relationship with you?"

"No. He believes in monogamy, and he married princess Iris."

"From what you told me, Marcus seems to be a fairly decent fellow, but taking you from your world only to have you sit on the side and not sparing any effort to train you, that is a very low blow." frowned Akeno.

Darkness nodded wordlessly.

"Well, that is in the past now. Noah and I will take care of you. We will give you happiness, Darkness. And we will make you stronger."

"…Yes." replied Darkness, with a barely audible voice.

Akeno smiled, and slowly brought her face closer to Darkness's. She gave her a gentle kiss, then pulled back, waiting for Darkness's reaction.

Darkness trembled for a second, then stared at Akeno for a long moment. Eventually, she made a small nod, and Akeno kissed her again, inserting her tongue this time.

Darkness answered with hesitation at first, but she got into it and eventually gave as much as she received.

After a few minutes of making out, Akeno pulled back.

"Who do you belong to, slave?"

"I won't submit to you, just from this much…" said Darkness with a sly smile. "That's why, if you want to conquer my heart, you will need to torment me a lot more."

"That's a given." smiled Akeno, tightening her hug for a moment.

"And then, you will have to remind me of it every day. Or I will forget it and rebel against you." said Darkness, her smile turning perverted once again.

"I believe in keeping slaves under tight discipline, as you will discover. But do not be too greedy for your Mistress's attention… I'd cuddle with you for a while longer, but you aren't the only slave I'm training, so you'll have to learn to share my attention."

Akeno stood and released Darkness from the ropes, before dressing her with black latex opera gloves and stockings. She took a chain and connected her collar to one of the bed's feet.

"I did say that I would chain you to my bed, did I not?" chuckled Akeno. "You have my permission to touch yourself as you watch me play with Medb, slave. Be grateful for it, because once your training is over, I will lock your juicy little snatch in a chastity belt, and you will only be allowed to orgasm once every few days."

Darkness, being the hopeless masochist she was, got even more excited by the prospect of having a chastity belt locked on her, but Akeno stopped paying attention to her and walked over to Medb, equipping Corruption once again.

Medb, still isolated in her own world, almost jumped in her bonds when Akeno touched her again, earning herself another electric shock, and moaned loudly in the hood.

Akeno played with her body for a few minutes, then removed the headphones.

"Do you want to cum, slave?"

Medb hesitated for a few seconds, then nodded wearily.

Akeno smiled triumphally as she positioned herself between Medb's legs, removing the vibrator and the electric prods.

Medb had just conceded her first major defeat, trading her dignity for pleasure and relief. With this precedent established, and once marked with the Thrall Crest that would increase her libido, it would only be a matter of time before the proud and dominant Queen accepted her place as Akeno's sex slave.