(Your POV)
"There once were a pair of nekomata, a pair of sisters. They were the only family they ever had, and they relied on each other with all their hearts. One day, the elder sister was recruited into a devil's peerage, and the elder sister began making a name for herself while finding a place for the younger sister to stay. One day, something awoke in the elder sister. The nekomata are capable of powerful magic, and this black magic awoke in the elder sister. In a matter of time, the elder sister surpassed her former master in power, and became drunk on her own power, killing the master and becoming a monster who seeks only combat. The devil faction hunter after the younger sister, fearing she would become a powerful monster like her sister. Then Sirzechs found the younger sister, broken from her sister's betrayal and the threats from the devils. Sirzechs granted the girl protection, and put her in the custody of me, where I gave her a new name...Koneko."

Rias gave me a full explanation of Koneko's past, and I understood why Koneko had trouble showing her emotions. "Koneko, are you okay with me knowing all this?" I asked whilst focusing on the small girl.

"Yes, you've done nothing but help me, so you deserve to know." Koneko stated, and I respected her choice to let me know. "(Y/N), how do you get stronger without relying on your blood?" I noticed Koneko started crying. "I'm completely useless as I am right now, even as a rook, I'm the weakest one here. I hate being useless..."

"I understand your ambitions, but the way you're going about it now will only hurt you." Rias commented as I grabbed onto Koneko's hand whilst using my other hand to wipe her tears, my way of letting her know she's not alone.

"I don't want to use that power...if I do, I'll become like my sister." Koneko looked like she was having flashbacks, and I squeezed her hand enough for her to snap out of it. "I can't stand the thought of it... (Y/N), how did you get stronger?"

"I did what only I can do, the same thing your sister did." What I said caught everyone off guard. "Everyone has something only they can do, whether you utilize that ability is entirely up to you. You will never become like your sister, and even if you do become a monster, which you won't, I will save you from yourself."

"How can you be so sure, I don't want to hurt you (Y/N)." The first expression Koneko ever showed me was right in front of me, and it was fear, an emotion that never suited Koneko.

"You won't, not only because I am the Ultimate Immortal, but because you're Koneko Tojo, the rook of Rias Gremory." I had a serious expression, surprising Koneko enough for her to suddenly embrace me in a hug, and one I knew she needed. "You are stronger than your sister, you possess more self control and strength than she does."

"But how will I know I won't go berserk like my sister did?" Koneko asked, and that was a hard question.

"You won't, it's a leap of faith." I decided to copy a line I heard from a movie I watched with Xenovia, but I wasn't going to tell Koneko that.

Koneko and I stayed like this until she stopped crying, then she broke the hug and continued eating the meal I made her using magic. Rias explained to me that Koneko was a Nekoshou, one of the more powerful kinds of nekomata. So Koneko would feel more safe about trying to utilize her Nekomata side, I promised Koneko I would make a neutralization drug and inject it into her should she get drunk on her power like her sister was. Unfortunately, our little reunion was cut short by a servant delivering some news. Apparently there was a kind of ball coming up, and I needed to get ready for it. I made sure Koneko was alright one more time before the servant physically dragged me out of the room, with Mule skipping right behind me.

I continued getting dragged until I arrived at an empty ballroom, there were pillars along the walls and arches between each pillar. The arches and pillars all held up a roof with renaissance-era paintings, the contents of which appeared to be of devil history. There were windows to let light into the room, and against the various walls were a variety of tables and chairs, moved out of the way for practice. In the middle of this ballroom, Grayfia and Venelana were talking. Grayfia was out of her maid uniform and wearing a blue ballroom dress, she didn't really put much effort into her appearance, since she wasn't wearing any makeup.

"Good to see you again (Y/N)." Grayfia greeted me with a bow, and I responded to this with a bow of my own before greeting her.

"Nice to see you again as well Grayfia." I greeted the woman, and the two of us agreed not to use honorifics when greeting each other.

"I'm starting to think both my children have similar tastes..." Venelana commented as she examined Grayfia and I, and the two of us tilted our heads in sync. "Anyhow, (Y/N), do you know how to dance? More specifically, in a ballroom setting."

"No, I'm afraid I don't know how to do dance in the sense you're most likely thinking of." I answered, while I did practice dancing from the Ultimate Dancer's notes, that was solely for evasive purposes.

"Then it's a good thing we called you out here, when going to a ball, it's a requirement to know how to dance." Venelana explained before gesturing towards Grayfia. "Grayfia volunteered to teach you since you two already know each other."

"Besides, I heard you recently learned how to cook, so now I get to have someone to talk to when it comes to recipes." Grayfia commented, and I was willing to take notes, but that wasn't the primary focus here.

"Now now, you two, don't get too excited over cooking, your focus here should be dancing." Venelana got our attention by clapping, then a record player began playing. "You two can practice together, and I'll overlook it."

"Understood, Lady Venelana." Grayfia and I bowed in complete sync of one another.

"I hope that Milicas doesn't inherit this family's taste in partners."

(Timeskip, brought to you by (Y/N) and Grayfia acting like a butler and maid for Rias and Sirzechs, the former of whom may have awakened a new fetish)

Grayfia and I danced for several hours until Grayfia got tired, so now Venelana and I were dancing. Thanks to my almost bottomless pool of stamina, I wasn't all that tired. While all the studying, sparring, flying, cooking, and dancing was tiring considering I got no sleep during that entire time frame, I was still capable of moving. After a while, I was finally able to dance without stepping on anyone's feet, all thanks to my unique trait where I can learn many things quickly. Venelana and Grayfia were both tired, so I grabbed a table and put it in the middle of the room. I placed some chairs down and began preparing a small meal for the two women. I grabbed a couple bowls from my bags on Mule and filled them with stew from the Cauldron of Plenty. I placed both bowls on the table before preparing drinks for the two women.

"Pardon me for asking, but what kinds of drinks do you two prefer to drink after a workout?" I asked whilst searching through my bags, I have a wide variety of items in there.

"I'll just take a water, and I'm sure you've been told this before you can become quite a butler if you so decided." Grayfia commented while I grabbed a water bottle from my bag, then I tossed it to Grayfia, who caught it.

"Personally I think he'd make a better husband for my daughter." Venelana commented, and she requested water as well. "I mean, Grayfia, you're a good mother, and (Y/N)'s similar to you in a lot of ways."

"Elaborate." Grayfia and I spoke in complete unison, causing us to look at eachother.

"Well you both are some of the most powerful pieces in your respective peerages, are incredibly reliable, good at just about anything you set your mind to, and..." Venelana dragged on causing Grayfia and I to turn slightly red. "...neither of you know how to take a compliment."

"I want to deny that, but I also don't wish to lie." I had both my hands behind my back whilst I stood at the side of the table, that is until Venelana told me to grab a chair and sit down. "So now that I've mastered dancing, what do I do now?"

"I honestly didn't expect you to learn this fast, but I suppose now we just talk." Grayfia commented, and all three of us just sat around silently, that is until Grayfia decided to speak up. "So how is your relationship going with the girls, specifically Rias."

"I believe Koneko is starting to fully trust me, Akeno and I haven't talked much since the bath house incident, and my relationship with Rias hasn't changed all that much." I answered, and I know I left out Asia and Xenovia. "I haven't seen Asia and Xenovia when I got back, so I can't confirm my relationship with them."

"Bath house incident?" Venelana was caught off guard by this, and I'm fairly certain all of us involved agreed to keep the incident a secret.

"Long story short, Issei and I were thrown over the bathhouse wall, and while Issei was shot back onto the other side, I was allowed to pass." I explained. "I ran out as soon as possible because I think jumping into baths of the opposite sex is a crime. Akeno flirty while I was in there, just more so than usual. I hope I didn't offend her when I ran out."

"I noticed that Akeno looked a little distressed while she was training." Venelana was recalling her memories of watching Akeno train. "If I had to guess, she's sorry about that."

"Sorry?" I tilted my head, I was the one who was thrown into the bathhouse and ran out, why was Akeno the sorry one? "It was my fault in the first place, therefore, the blame falls solely on me."

"Yes, but you said she was flirting and/or seducing you more than usual." Venelana was observant, I didn't want to say anything about Rias flirting too, since this was her daughter here. "Akeno must know how bad you are with seductive situations, and now she's thinking back on her actions. She must think she went too far."

"Are you secretly a mind reader?" I asked, and I was half tempted to learn mind reading to figure out what's bothering everyone so I can help them without them saying anything.

"No, I just have a lot of experience with dealing with people." Venelana laughed slightly at my suggestion of her being a mind reader, but half of me is still not convinced. "By the way (Y/N), have you tested out that sniper rifle Sona gave you yet?"

"I have not used the M82 yet because I'm always focused on keeping my allies safe by taking on the role of front lines by myself." I explained, since the M82 is a sniper rifle, using it in close quarters is much harder compared to using my Lauer.

"So you're saying if you didn't have to focus on protecting your allies, you could utilize your full capabilities?" Venelana asked, and I never thought about it. "If you can control the terrain to give you the home field advantage and rely on guerilla warfare, you could easily become the most dangerous rook piece in all of hell."

"Controlling the terrain?" I asked, and it took me a minute to think. "You mean like utilizing landmines and such?"

"Close, but not quite." Venelana took a bite of the stew I got her. "Unlike Rias and Akeno, you specialize in transmutation magic, and like the name suggests, the magic focuses on altering the area. Since you're also learning the skills of a druid, I was thinking you could learn how to create thick environments of trees and bushes, using the terrain to your advantage. If you created the forest, you should be able to utilize it to the fullest without slowing yourself down."

"I see what you mean, and that's not a bad idea." I thought of the idea, suddenly introducing an opponent into an unfamiliar battlefield would force them to adapt to their surroundings, but it could be troublesome if they use AOE magic. "What if they utilize AOE magic?"

"What if you create a magic canceling poison?" Venelana suggested, and she was smart. "Granted, poisons like that only work for a couple minutes but that could provide an opportunity perfect for you."

"I recommend waiting another time to do more training, it's gotten rather late and you're covered in sweat." Grayfia pointed out. "Go ahead and take a bath before going to sleep, you've come the farthest in the short amount of time, you've earned it."

"Thank you, Grayfia."

(Timeskip, brought to you by (Y/N) in his seal form swimming by)

It was evening, and unlike the previous days, I was actually preparing to rest. I was wearing my usual set of pajamas whilst cleaning some of my equipment and sitting on the edge of the bed. The tool I was cleaning right now in particular was my combat knife, the white cloth I was using was coated in a special oil from here that is said to increase the blade's effectiveness. It was dark out, so I had a nearby lamp on. Mule was charging against the wall, along with my primary weapons. Genbu, Gae Bulg, Crimson Javelin, Solais, M82, Akimbo Grims, M1 Garand, Lauer, and some random steel chain I found. I didn't really have anyone to fight right now, so my wide arsenal was kind of just for show for now. I was sharpening my knife until the door opened. I saw both Xenovia and Asia walking into the room with their pajamas, and both were carrying pillows.

"Good to see you guys again." I put my knife on the nightstand, and Asia hugged me once she saw me, making me glad I bathed before coming to bed. "How was training for you guys?"

"I kept on accidentally injuring myself, and Asia had to heal me over and over again." Xenovia informed me, and I began getting concerned. "The good news is that I feel stronger now."

"Good job, but please keep injuries to a minimum." I requested, and Asia told me her training was going well. "So what's going on you two, do you need something?"

"I was wondering if it would be okay to sleep with you, it feels weird sleeping in such a big bed by ourselves." Asia explained, I looked at my bed, and it was larger than a king sized bed.

"If you feel as though it will help you, then the bed is yours." I gestured to the bed and put my knife in the sheathe, which thanks to the odd shape, it was hard to do.

With that said, the three of us decided to go to bed. Xenovia was wearing a dark blue tank top with shorts, while Asia wore a nightgown. I slept between the two, and thanks to the bed's massive size, all three of us had some space between us. Xenovia was on her side, facing away from me, I was on my stomach, and Asia was already asleep. Unsure of what to do, we just decided to talk.

"I take it you're having trouble sleeping?" I asked the blue haired girl, who rolled over to face me in response.

"Yeah, I've just never slept with a guy before." Xenovia explained, and it was understandable, I was nervous when I first slept next to Rias, but then again she sleeps in the nude.

"I understand, and if there's anything I can do to help you feel more relaxed, just let me know." I stuffed my face into the pillow. "I'll turn into my seal form if it helps you, I have been told my seal fur is soft."

"No need, I'll get used to sleeping like this if it's for you." Xenovia agreed whilst she looked at Asia. "Asia seems quite familiar with his way of sleeping, do you have anything to do with that."

"It's quite cold close to the ocean for her, Rias, and Akeno, so sometimes they join me in bed, for sleeping of course." I explained before Asia suddenly rolled onto my back, and I could feel her breathing on my neck. "You and I ignore it because it's not that big of a deal."

"I have heard it's easier to sleep clinging to someone you love, is it okay if I try it?" Xenovia asked, and I agreed to let her sleep while clinging to me. "Okay then, thanks (Y/N). Goodnight."

"Goodnight, Xenovia."

(A/N: I feel as though there's a fact about Rias we always overlook, she's a nerd. And by that sense, I mean she loves Japanese culture, anime, and video games. That little piece of information has so much potential, and even I didn't know about it until Lawliet_Aftermore (who started writing his own fanfic called The Unknown with Potential, so check it out) told me about it. That also made Rias tied with Rossweisse for 1st place on my best girl rankings. Keep in mind, my favorite waifus are the precious and/or gamer girls. Have different tastes than me? Coolio beanio. Waifus are like colors, beautiful and everyone likes a different one. Like colors, it is also stupid to argue with someone on which is the superior waifu, since we all have different tastes.