"I wonder what discoveries your friend will make in the near future," Rias posits as you recline on the decking at the back of your new mansion. A pair of cheap sun chairs were all you needed to relax and enjoy the nice weather. The sounds of drilling and hammering do put a damper on the experience somewhat.
"It'd be nice if we could expand the capacity of the Sledgehammer, or maybe even design a way for you to come and go as you please into our world."
"Our magic may be able to help. The Underworld is technically a different plane of existence. Transferring ourselves in and out is very important." Rias becomes more impatient by the second as she lays back with her legs crossed. It quickly reaches a boiling point and she shuffles over to the edge, bridging the gap between both chairs and clinging to your side.
"You've been very interested in touching me recently," you note. She immediately put herself between you and Venelana during your walk. Though that wouldn't have happened had she not ceded the position out of respect. It's not a problem per say. You will never complain about having such a gorgeous girl clinging to you.
Rias pouts and looks away, "I may put on a confident demeanour around my precious subordinates, but even an icy girl like myself wants to be held from time to time." You reach out and wrap your arm around her waist, pulling her close onto your chest.
"Speaking of subordinates, how has Asia been?"
"She's adjusting well. She is honestly the last girl I expected to fit into a devil's peerage, but she never lets the changes in her life shake her resolve. She's made many fast friends due to her sacred gear as well. Her bragging about the date we shared has caused some issues…"
"She bragged about that?"
Rias giggles, "Yes, very much so. Akeno, Koneko and Xenovia were very interested to hear how things went."
"Even Koneko?"
Rias set her brow and imitated Koneko's voice, "She 'wanted to make sure that you didn't do anything dirty' to her."
"I don't do anything like that on a first date."
"Oh? I do seem to recall that Akeno and I were granted the privilege of sleeping with you almost immediately."
"Hey, that was only because you two jumped on me like a pair of hungry lionesses. I want to make sure that everyone is comfortable with it before they do anything like that with me."
Rias is enjoying teasing you with that one. You've become acutely aware of the many conflicting interests that come about as a result of her personality. Headstrong and domineering, but needy and romantic; serious and stern but also a tease. That isn't anything special. You feel your own personality shifting when you're around people you are comfortable with. Seeing her in the flesh is enough to stun you into silence. Her vibrant red hair, the subtle gradient of her skin, and of course the immense curves of her body that could only occur as the result of devil magic. It's hard to believe that she's real, in your arms at this moment, and that she loves you unconditionally too.
"I think Asia would be more than happy to take your relationship to the next step," Rias says, "Even Koneko feels the same way."
"Really?"
"I know her better than anyone else. Koneko has always tried to hide her feelings. She thinks she's being smart when she asks us probing questions about you. She never left the room when we watched your television series together."
From your already learned knowledge about Koneko, there's a good reason for that. She doesn't want to cause damage using her immense powers. It's clear from her behaviour and Rias' statements that she has not yet learned to control them. Whether that will happen without your intervention remains to be seen. It's a matter of course that Koneko is also in love with you – Mitsuru dug for a DxD universe where every single woman (aside from Issei's newly created girlfriend, perhaps,) would drop everything just to be with you.
In terms of ambition – you don't want to go too crazy over there. The rest of the Occult Research Club seems like a good stopping point. Perhaps you'll pick up a few others depending on how things develop. As chauvinistic as it feels, you want to make sure that you don't just fill your harem plate exclusively with devils and angels from the DxD universe. There are so many untouched places left to explore!
"And what about you?" you wonder aloud, "How would you feel about the rest of your peerage joining us?"
"As I already said, for devils a greedy husband is entirely natural. I'd be disappointed if you didn't lay a claim to them."
"Not like that. I mean, personally – how would you feel?"
Rias smiles, "I think it would be wonderful. You may not fit the definition of a traditionally in-demand devil, but I believe you are even better. I love my peerage; they're family. Allowing them to enjoy your company in the ways that I have is the least I can do." A surprisingly generous answer. That was what you wanted to hear. Rias just going along with it because that's how 'devil society' operates would have cooled you to the prospect just a little. You feel more confident in doing it for her now.
It might be easier to focus on Asia and Xenovia first. Xenovia is… Xenovia. Her entire thing is demanding sex at the drop of a hat; she has a very odd desire to get pregnant. Asia also has a lot of desire bubbling underneath that calm and kind surface. Then you can worry about worming your way into Koneko's heart. The start of a plan begins to form in your mind. You'll need assistance from Lala to make it happen.
"You're thinking about something dirty, aren't you?"
You shake your head, "No. Not at all."
"Hm. That look on your face…"
"I promise. It's nothing sex related."
"I wouldn't mind if it was," Rias replies, quick as a whip.
"Yeah, well – we aren't going to get much privacy with all of these workmen here."
"I could form a magical seal and hide us from sight."
"Too much effort. Let's just wait until they're gone."
"…Agreed."
Later that evening, after everyone else had cleared out of the mansion and Venelana had gone home, Rias got her wish and spent some time with you on the solitary bachelor mattress that inhabited the bedroom. The novelty was quickly starting to wear off. Bring on the large, gothic harem bed any day.
When all that was said and done, you decided to enact the first step of your plan. There was no work planned for the mansion the next day, and the basement area had already been completed. You stood in the long, winding hallway that split off into a dozen empty, windowless rooms and summoned Lala from the void.
"Hi hubby!"
You are nearly bowled off your feet the instant she appears. You return the embrace and cop a feel of her butt before she backs away. Her tail wiggles happily as she notices that you are starting to become more intimate with her during normal interactions. She can't stop herself from leaning up on her toes for a kiss, which you happily dispense.
"This is our new place," you explain, "I was hoping you could give me a hand with something."
"Anything you need!" she chirps. She reaches into the pocket of her dress and recovers a small handheld device.
"I was hoping we could build a kind of training chamber down here, using the compressed space thing. It needs to be tough enough to survive anything we throw at it." Lala nods and dutifully notes down your requirements into what you discover is a handheld supercomputer. A moment later it pings and spits out a series of numbers and stats for her to intake into her sponge of a brain.
"That should be easy! Our palace has a bunch of secure rooms like that where Dad keeps all of his treasure. You can't get inside without ripping the planet to pieces and digging through the remains."
"Sounds good to me."
"Are you using these doors for anything else? I can copy the garage's bedchamber and bring it here!"
You scratch the back of your head, "Sure. We have room to spare in this place. Just pick a door and go crazy."
Lala hops from door to door, pulling them open and peering inside. Some of the rooms are more habitable than others. One of them is seemingly intended to store a copious amount of expensive alcohol, the others remain a mystery. Why Lala feels the need to inspect all of them before she makes the door lead to a pocket dimension is also unknown. It really doesn't matter which one she uses.
"I'll have to bring some of the materials with me from home, but it shouldn't be hard! I can just store them using one of my cute devices."
"Just send me a message whenever you're ready to go. I can summon you. I'm going to be spending most of my time here making sure everything is getting done."
"Okay!" she cheers. Again, she leaps across the floor and wraps her arms around your neck. You hold her up with one arm and allow her to have her fun. You surprise yourself by displaying the strength needed to carry her like this – as light as she is versus the likes of Motoko.
"You've gotten stronger. I like it!"
Lala likes everything. Unless you happen to be a weird suitor from space, that is.
With your new invincible training chamber, Koneko will have a safe place to test out her powers, but it'll also prove useful for other things too. You can transform and get used to the suit without having to worry about prying eyes or damage to the surrounding area. In the future you could integrate it with the shooting range that Mitsuru had built in the garage.
"Since you're here, why don't I show you around the place?" you suggest. Lala nods happily, but refuses to hop out of your arms. You sigh and turn back to the stairs – it looks like you're going to be princess carrying her everywhere until she gets bored of it...