After waking up from her nap Koko stretched sligtly before she got up and started gathering some materials for her new defenses. Now that she had a better frame of reference for the 'average' strength of this world's supernatural she felt the need to increase the defenses of her scrapyard. Thinking for a bit she temporarily shut down the FYM before starting on machine that would increase the energy it was given by gradually turning the surrounding mana into whatever was put into it.
A few hours later multiple machines resembling water tanks was arranged in a circle in front of Koko in one of the rooms located deep into her underground base. Walking around and making sure nothing was wrong for a few minutes Koko eventually stopped in front of what looked like a pedestal with lines running down it's sides and a circular slot carved into it as she took out a marble glowing in various colours from one of her pockets.
This was one of the side projects she had made over the years that littered the underground base, it was initially created because Koko was a bit curious of why demonic power just did not want to heal, at all, and created a ball of demonic energy and started slowly introducing holy energy to it which she found out was what lingered on the lightsabers and guns she found a few years ago.
Everytime it reached a certain point the crystallized ball of demonic power would be 'eroded' by the holy energy and disappear not long after. Koko tried a few more times before giving up and decided to try a different method which lead to her creating a sort of neutral energy crystallized into the shape of a sphere whose sole purpose was to integrate other energies into itself.
This time when she introduced both demonic power and holy energy they were swiftly assimilated without any problems. On a whim she decided to assimilate a bit of psychic power as well which it also did without problems. Finding the colors changing with each new energy that was introduced fun, she started carrying it around with her just in case she found something new.
She had also taken it with her on her road trip and it was now swirling with dozens of different colors. Putting it into the slot the lines running down it's sides lit up as the energy was transferred into one of the containers before it started sucking in the surrounding mana, gradually increasing it's quantity before sending it into the next one and repeating the process.
Watching for a few minutes to make sure it was running smoothly Koko eventually started working on the next step in her plan to making her scrapyard impenetrable. What she was currently making was a sort of core that would project a shield she could change the shape and size of around her scrapyard. This shield however was also able to absorb most of the energy of whatever hit it's surface, whether mundane or supernatural in nature, about 80% would be absorbed before the impact.
After she finished, she carried the football sized core to the room the Quantity Amplifying Array or QAA was in and made another small pedestal in the middle of the formation before placing the core onto it.
Now that they were done, she just had to make it so that the absorbed energy of whatever hit the shield was funneled into the QAA to further amplify the energy that was already there. Basically making all the attacks that landed on the shield supply it with more power than it was using to defend against the attacks in the first place. Not to mention that if the energy used was already assimilated, the quantity will grow even more than with the surrounding mana.
Meanwhile when not in use, the QAA would continiously make more and more energy, making the shield stronger with time since the only way to destroy it was to hit it so hard the energy powering it was used up, and with all attacks only doing 20% of the total damage they would have done otherwise, that would be next to impossible.
Getting done a few minutes later Koko activated the core making it light up and start hovering as a thin flim of shifting colors shimmered to life a few centimeters above it's surface. Mentally commanding it with another administrator chip she had fashioned into a black earring she placed on the helix of her ear, the shield started gradually expanding before it disappeared into the walls, eventually encompassing the whole scrapyard and the underground base.
"Heh, try getting through that one." Koko dusted off her hands with a satisfied face before walking out of the room. She had also added the FYM to the core setting it to activate if any hostile beings breached her shield or manually through her administrator chip.
---
Okita was relaxing in the club room of the ORC watching Rias and her peerage interact when the walkie talkie that Koko gave him started vibrating. Hmm, was Koko back again? Taking it out of the inner pocket of his kimono sleeves, he ignored the curious looks he got as he answered. A few seconds later Koko's now mature sounding voice rang out, though with the excitement she seemed to always carry.
"Century Geezer, I'm back!" Okita heard Rias and Kiba spitting out their tea and start coughing as he languidly answered.
"Hoh, I see. You were gone for quite a while and I couldn't catch you the few times you returned to your scrapyard before you left again."
"Yeah! I'm back for now though, I kinda missed my scrapyard and Beo."
"I see. Would you mind if I resume my visits to your scrapyard?"
"Nope, that's fine. I'll have to change the signs I hung on the gate though, I'll go do that now, see ya!"
"See you soon, Koko." Okita put the walkie talkie back into his kimono sleeve when Koko hung up before taking a sip of his tea and relaxing again, still ignoring Rias and her peerage looking at him in confusion.
As the silence stretched on for a few more minutes Rias and her peerage sort of looked at each other communicating with their eyes before Rias spoke up hesitantly.
"Um Okita-san who was that?"
"Hmm? That was Koko." Okita answered nonchalantly. Rias looked back at her peerage in and saw them staring back with just as much confusion.
"Oh... is she your um, relative?" Rias tried.
"Nothing like that, though I do occasionally think of her as a mischevous granddaughter of mine." Okita hummed slightly as he continued relaxing. He had achieved enlightenment in the way of wheathering the storm that is Koko during the few years she was out of town and gotten alot calmer and harder to throw off. This actually helped him alot in fights, managing to stay calm under greater stress and also oddly in furthering his swordsmanship.
"Oh, does she live near Kuoh?"
"I suppose she does, yes."
"I see." Rias said as she went quiet again while looking back at her peerage. The silence continued for another few minutes before another voice spoke up.
"Okita-sensei, is it possible for us to meet her? I'm a bit curious about what someone you regard so highly is like." Kiba asked as he tried to imagine what 'Koko' would be like. Based on their call, she was probably a very carefree person. However, her disrespect towards his teacher also slightly grated on his pride.
Okita raised an eyebrow as he looked at the curious faces of Rias and her peerage. Should he introduce them to each other? Thinking for a bit, it was very possible it would actually give them a very much needed reality check of how powerful some beings outside their family was. Rias and her peerage was often surrounded by powerful people, his king, Grayfia, his king's peerage, her mother, the list goes on.
But since they were so familiar with each other, their power never really registered in their minds. They felt like they were safe as they were and didn't need to improve with any sense of urgency. Okita knew that Rias wanted to get out of her arranged marriage and his king had already made arrangements for it to eventually end in a Rating Game, something Rias was already banking on to win her freedom.
However, she and her peerage barely trained at all.
Now that he had so much free time he occasionally trained his old student, however, he only did so when asked, and the times Kiba had asked for training since he was stationed as a bodyguard could be counted on two hands.
Giving them a glance out of the corner of his eye he eventually decided to have them meet and run the plan by his king before proposing a spar between them.
"Sure. I'm going to visit her in a few days, you can join me then."
Rias and her peerage nodded before going back to talking though with a slightly different topic.
---
Later that day Okita used a communication spell and explained his plan to his king.
Sirzechs was quiet for a moment before a deep sigh sounded from the magic circle. He knew that Rias was spoiled, he was a major contributor even, but as much as he would like to be able to say that nothing would happen under his protection, he knew that was untrue. He knew that he couldn't constantly watch over her because he was worried about her being in danger.
He could try, but his duties as one of the Satans ate up alot of time and he'd rather she suffer a bit in a controlled environment and grow stronger than freeze when something dangerous eventually appeared. He knew a bit about Koko's character from asking Okita and knew that she didn't care about Rias being a heiress so she wouldn't sugarcoat anything which made him a bit worried.
"Go ahead Okita, however I'm sending Surtr Second over as well, just in case." Sirzechs said eventually.
"Got it."