It's another slow day in the garage. Mitsuru has gotten the surveillance system up and running on the new and improved central computer system thanks to Barbara lending her the AI system needed to operate it. According to her, your ability to both respond to new crises and crunch numbers had increased a thousand-fold. Mitsuru is going on a shopping spree, hammering in a set of new alternate universes to plunder of their single woman every other day. She's travelling down a list of every piece of media you've ever consumed – and some that you haven't, just in case you need it.
You can't supervise her at the moment though, because a certain red-haired devil is trying to monopolise you to make up for recent isolation. Rias puts on the airs of a refined and cool lady, but in truth she's definitely the neediest girl in your harem. She always wants to spend more time with you, and she starts to get lonely if you don't see her in person every few days. Motoko has been so busy with her work that you haven't seen her in a month, and she doesn't complain…
Rias leans in and leaves another red mark on your face by kissing your cheek; "I hope that you'll make good wives of the others soon, husband. It would be very unfair to enjoy myself while leaving them out of things." It's such a stark contrast to the jealous Rias you know from the original series, but that's what happens when Mitsuru specifically locates worlds where they all accept polyamory like it's a normal thing.
"Of course I will. Xenovia is already on board. I just need Asia and Koneko, I think."
"Asia very much enjoyed our date together. She's looking forward to the next."
"Me too. I should organise something for us that we can do as a group."
Rias shoots you a steamy look.
"Something that isn't sex."
Her face falls as you shoot her down. She pouts, "Really?"
"We can still do that – it's just… something that comes at the end of the date, not being the whole thing. You'll never find me turning down the chance to get my hands on you, Rias." You punctuate your flirting by reaching around her back and placing one of your hands on her chest. Rias smiles and blushes.
"Good. A devil should be filled with boundless desire. As the future male head of the house, you will be expected to bed many, many concubines and sire children as a sign of your virility and strength. Given your ambitions, we may have to request more of that drug from Lala."
You grimace, "Right. More of that stuff." You really hope that it doesn't have any side-effects, Lala doesn't do her due diligence with some of her inventions. The discussion is interrupted by Mitsuru coughing into her hand and walking up to the couch. Rias smiles and waves at the short scientist, who returns it in kind.
"Since both you and Rias are here, I thought it might be the perfect time to explain our next major project. Venelana and I have been working hard on formalization our methodology, but it's pertinent for Rias to know as well."
"Alright. What's going on?" you ask.
Mitsuru escorts you and Rias to the elevator. She presses a complex combination of numbers to reach a normally inaccessible floor. The motor begins running and lowers you into the depths of the earth while Mitsuru lays out some context.
"To put it simply – we're developing a portal network that can transport people and objects between universes."
"A portal? Is that different to the Sledgehammer?"
Mitsuru adjusts her glasses, "Allow me to explain how it works. With something as compact as the Sledgehammer, the stabiliser device that aligns their existence with our universe can only be so large. I've made efficiency improvements before, but at the present time the only way to make any further leaps would be to make it even larger."
"And then it wouldn't be a very good weapon."
"Precisely. So along that line of thought, I realised that I should do just that. A larger stabilisation system that will allow our allies to come and go as they please. With some security caveats and failsafe protocols in place, of course."
The doors slide open and reveal a gigantic, mostly white chamber with a ceiling that seems to climb infinitely into the sky. Several metallic rings have been placed around the perimeter of the room, with digital signs awaiting instruction so that they can display where they lead. The centre middle portal is placed in front of a control panel. There is some indication that the full structure and mechanism is actually located beneath your feet.
"This portal will lead to the underworld. There's an identical chamber being constructed under the Gremory manor as we speak. Once it is complete, our devil allies will be able to come and go as they please – with a significantly increased limit as to their number."
"How many?"
"Enough to not worry about the specifics," she quips, "But if you want an accurate figure, the stabilization device beneath our feet is capable of tethering around five-hundred people at once."
"You have to build one of these in every world we pull from."
Mitsuru shakes her head, "The version I've had Venelana construct in their world is much simpler than this one. It merely needs to serve as a conduit by which the central computer can detect and open a doorway for them. It essentially dispenses a signal and leaves the hard work to us."
"Oh, cool."
"I believe Venelana was also presumptuous enough to build a second node in your new house."
She was? You haven't even had the chance to explore every room in the damn place just yet. She must have snuck it into the basement.
"So we can teleport from my house to here?"
"That's right. Now, we can jump instantaneously from the Gremory manor, to here, to your own mansion in the blink of an eye." Mitsuru pauses and walks back on her own statement soon after; "Sorry. We can't go to the Gremory manor just yet. That would require programming a pair of cards for ourselves and the construction of an appropriate receiver on their end."
"Huh, so how do the others get back?"
"Each universe has its own gravity so to speak. The stabiliser allows us to bring and keep outside individuals in our universe. When the stabiliser is told to send them home, it is disabled and they're pulled back automatically like a rubber band having its tension released."
You whistle and admire her handiwork, "Do you think we could someday soon?"
"I'm working on it. Now that the central computer is speeding through my allocation of universe searches, it has much more time and power to dedicate to running simulations. It'll require some time and cooperation with Venelana, as I can't be there on the other side to direct construction. For now, I'll have to think of a way to communicate the technology and blueprints to them, and then we have to worry about getting the right materials."
"It's a good thing you got that future paper from yourself."
"It unhelpfully redacted to ensure that I can't take shortcuts," Mitsuru sighs, "It contained the exact amount of knowledge required to make my own breakthrough, and nothing more. Now; I heard you wanted to host a housewarming party with the ORC and friends?"
"Sure. Do you want to come along?"
Mitsuru opens her mouth to reject the offer like she always does – except that she pauses, considers it for a second, and then says something extremely uncharacteristic; "I'll find an opening in my schedule."
Wow. This is the first time she's accepted attending a social function with you in years. Rias smiles and claps her hands together, "I'm looking forward to it. It'll be the first time that everyone is together on this side."
"The current estimated time of completion is two weeks from now, so plan your party appropriately."
The limitations of the new system are obvious. It demands that you personally transport the summoned people from the garage to the location of the battle, meaning that the Sledgehammer will remain the quickest and easiest way to summon assistance when you need it. Additionally, constructing the relays in each universe is an expensive and time-consuming process. You'll need a cooperative party of people and a safe location to construct them.
Rias winks at Mitsuru and mouths something to her. They've become a lot closer since you resolved the bomb situation, it turns out that protecting someone's life is a good way to get into their friend circle. These two make a pretty good team. You wouldn't want to be on the other end of them. The Ruin Princess and the smartest woman on the planet – that's a recipe for trouble. Mitsuru has more work to do on fine tuning her system, so you leave her to it and head to one of the private rooms with Rias.
You open a random door and find a lovely lounge and bar area that Mitsuru or Lala built for fun. There's even a pool table! Rias is immediately taken with the long lounge area against the back corner, she slips inside and pats the spot next to her with a smile. You don't know if Mitsuru has stocked this place with alcoholic drinks, but the atmosphere is thick and the smell is strong. It's like a real bar. Rias doesn't strike you as the nightclub type, but there have been bigger surprises since you met her.
"I'm excited to get the whole club together to celebrate with you. Not that the boys will be interested in joining in with us…"
"Really?"
Rias rattles off their excuses by counting on her fingers, "Kiba isn't a fan of social engagements, Gasper is too shy, and Issei's girlfriend may kill him and mount his stuffed body above her fireplace if he gets out of her sight while surrounded by inebriated women."
"You make her sound… very intense."
Rias grimaces, "She is. Not that I think Issei should break up with her. They're perfect for one another. She's just a little possessive of him."
A little? Every time anyone has mentioned her its usually in the content of maiming or killing Issei for being around other women. Your curiosity is only growing by the second, but you can't exactly travel through into the DxD Universe just yet. You're going to have to wait and see if Mitsuru can implement her new plan. Rias is visibly bored by talking business though, and the way she wraps her arms around your neck, before pulling you down into her breasts is plain evidence if any.
Rias sighs, "I wanted to spend some time relaxing with you. But I've been rather busy lately, I've introduced a new member into my peerage."
"Rossweisse, I assume."
Rias blinks, "Why yes, it is. How did you…" It takes her a moment to remember that you know these things, she rolls her eyes and nods; "Ah. I see. Rossweisse simply couldn't wait to join us once she learned about our health benefits."
"Why would an immortal devil even need health benefits again?"
Rias pouts, "We can still get sick! Besides, I was worried about what we spoke about last time. I hesitated to add her because I wanted to save an evil piece for you."
"I never made a decision on that."
"Well, my mother had a word with me and explained that she could simply utilise one of her pieces instead. Her peerage is extremely small, a few pawns that help around the manor, though I've heard that she's organizing something special in the future."
"Special? What does that mean?"
Rias shrugs, "I don't know. Mother can be very secretive when she wants to be. I assume it has something to do with trading or acquiring more members. She's starting to think that she needs them to protect you."
"Huh. How often does that kind of thing happen?"
Rias hums, "A lot. There are always ambitious devils looking for the strongest possible peerage members – and what fits one plan may not work for another. As a result, there are always movements between the families with loaning and trading. My peerage is already very effective, and I no longer have any evil pieces to use, so I don't do it myself. Mother will be able to demand a lot thanks to our family's reputation, but I do believe she's searching for a good deal, so to speak."
"It's down to personal preference then."
"Indeed. Some like Riser Phenex are always shifting from person to person, though he utilises his peerage more as a personal harem than anything else. None of them are safe from being pushed aside when someone else catches his eye."
"And that's why you don't like him."
"There are more reasons than that, but yes, an arranged marriage with such a boorish oaf would be terrible."
You really don't see how this situation is much different from what Riser is doing, but Rias is personally biased to like you more than him. Riser is a real asshole too – so even the basic elements of their relationship would be on shaky ground if it were to happen. Issei has already put him in his place and helped her dissolve the agreement, which was oddly the moment in the original story where they started to be an item. Clearly things didn't happen that way for Rias and Issei this time.
Rias' eyes smoulder with intent, "And I'm sure that he's much worse in bed than you as well…" Her hand reaches down and gropes the front of your pants.
"In the bar?"
"Nobody is going to see us! Let's have some fun!"
You're not one to turn down the chance to have sex with Rias, you relent and lean over to kiss her on the lips. "Alright. But it's going to be a pain to clean up when we're done."
"I'll use my magic, promise."