Highschool DxD: Reincarnated in a Crossover We Designed

Serafall, Lord Sitri, Lady Sitri, and I spent the time until dinner discussing the circumstances of my stay at the Sitri manor. 

Firstly, Lily and I would be joining Sona for her magic lessons which were conducted personally by Lady Sitri. Although Lily couldn't yet use devil magick, she could learn the theory in advance since she would be able to once Ajuka finished modifying my queen piece for Lily.

Secondly, we would both be recieving additional etiquete lessons to help catch up to Sona before we joined her lessons. Naturally I would be a part of devil high society and would need suitable manners and so would Lily as a member of my peerage.

Third, we would receive lessons on devil history alongside Sona from a dedicated tutor the Sitri family employs and I would receive supplemental lessons from Lord Sitri, when there was time, on the political climate.

While I was wise enough to understand the intricacies of politics due to my reincarnation, Lily was too young so she would take lessons alongside Sona when they grew up some more.

Other than that there were no duties assigned to me.

When I questioned this Lady Sitri gently explained that whilst I may be mentally old enough to carry out duties, to anyone not in the know I was just a year or so older than Sona. Thus, I should be following the same sort of schedule which would result in a lot of free time.

Whilst the devils and other aristocratic societies may nurture their children to fulfill their duties as nobles, most children were still given a large amount of time to play and develop hobbies especially when they were not even teenagers yet.

However, I wouldn't mind every now and then but realized I would quickly get bored playing ith Lily or Sona. Seeing me wondering how to spend my free time, Serafall suggested I go through the records in the Sitri library and start comparing their contents to the history I knew.

She phrased it in such a way that Lord Sitri agreed it would be interesting to discover the differences between the history of humanity in my world (without supernatural) to this world (with supernatural). Although I believe Serafall was really suggesting I focus on the supernatural side and compare it to the knowledge from the novels.

At one point during the discussion, Serafall did point out that she would probably end up taking me to meet the other Satans, most likely 'Juka-chan', even after the meeting later this week so having a bit more knowledge about this world would help.

The conversation continued the three Sitri's explaining several things I was curious about. One such thing they explained was that my social debut would be somewhere around my tenth birthday.

I had to get Raphael to check when my birthday actually was since I didn't know, and found that I was about a year and a half older than Sona.

Eventually, a maid came and informed us it was dinner ending the conversation.

-----

Dinner was a very fancy 3-course meal held in a large dining room complete with a massive wooden dining table and paintings hanging on the walls.

Sona and Lily naturally joined us for dinner and I was relieved to see that despite such a large table, all six of us were sitting around the same. Although it was a bit jarring sitting at a mostly empty table.

Throughout the meal, Lady Sitri led the conversation focusing on Lily and Sona with Serafall occasionally joining in while Lord Sitri and I mostly listened to the conversation.

Sona as equal parts pleased and upset when Lady Sitri explained the circumstances surrounding me and Lily. Naturally, she didn't include any of the complicated stuff like my reincarnation and Lily's memory problem.

We agreed during our previous conversation to only tell her in a week when Lilly will forget today if Ajuka and Raphael didn't manage to come up with a solution by then.

Sona was happy to have a friend around her age since until now everyone in the estate had been significantly older than her and she had to play alone. She naturally hadn't been taken to the human world yet, so she hadn't brought back Tsubaki as her future queen and she and Rias were still a bit too young for their families to introduce them to each other.

What she didn't like was the idea that I would be Serafalls son.

She seemed to think that I would take up more of Serafalls time leaving less for herself.

She was right about me taking up more time but, given Serafall's sis-con tendencies, I doubt it would impact the time she spends with Sona.

More likely she'll end up ditching paperwork when she spends time with me.

Once Serafall had cleared up Sona's worries and promised to continue spending time with her, the two little girls at the table began excitedly describing hat they had been doing. Though it was mostly Sona doing the explaining considering Lily seemed shy in the presence of people she didn't know.

Sona had first taken Lily on a tour around the mansion, accompanied by a maid, and showed her places like the ballroom used for official parties; the indoor swimming pool; the large bath/artificial hot spring; the indoor greenhouse; and the library before finally going to her own room.

There were many other facilities in and around the Sitri estate but these were the 'interesting' ones according to Sona. It seemed she had chosen places that appealed to her.

The ballroom, which I imagined to be expansive and quite decadent or even gaudy, would be awe-inspiring to most adults let alone little children.

The bath and swimming pool were possibly some of Sona's favorite places due to her extremely high water affinity from her Sitri blood.

The greenhouse would be like a place to explore for the young girls due to its very vibrant and exotic plants.

Considering she was in the library when we arrived, she may have already begun down her path of intelligence and found joy in learning. It was equally possible, however, that she was simply interested in the stories housed there.

Naturally, the most important place to her was her own room, where she had roped Lily into playing with her until they were called to dinner.

They were quite embarrassed when they accidentally let slip that they'd had an argument when visiting the pool. They couldn't remember what started it but it resulted in them arguing over who was better between me and Serafall.

They had apparently reached a stalemate when they ran out of arguments and were silent until they started exploring the greenhouse. At this point, they had forgotten why they were ignoring each other.

I had to hold back a chuckle when Sona revealed that Lily had called me Onii-chan in the midst of their argument and Lily hurriedly tried to get her to stop talking. She failed and was met with a cute head tilt from Sona who hadn't yet realized that Lily was embarrassed since we weren't related.

Once they'd arrived at Sona's room she had apparently begun showing off all her stuff, especially her magical girl costumes. She had tried to persuade Lily to join her in trying on her magical girl outfits but was shot down. Once Sona's persuasion failed they simply played together in her room until dinner.

At this point Serafall began demanding to be there when they dress up as Magical Girls in order to see 'Magical Girl Lily-tan's' first 'transformation'.

Lily still seemed quite reserved around the Sitris but from their story seemed to have opened up a bit to Sona and could in time develop into a friendship, helped by their close age. 

-----

After the meal was over Sona was taken away by one of her tutors for her scheduled history lesson. Lily, having become tired due to all the excitement from leaving Cleria's, visiting Ajuka's lab, and exploring the Sitri estate, stated that she wanted to go to sleep.

This resulted in Lady Sitri personally showing us to our rooms, with Serafall tagging whilst Lord Sitri left for his study to do some work. The room Lady Sitri showed us was even larger than the one at Cleria's mansion in the human world and in the same area of the house as Sona's.

This seemed to be a subtle gesture showing that they accepted us, or more specifically me, and our status. The corridor e stood in had many bedrooms including Sona's at the far end suggesting it was prearranged for the Sitri heir and her peerage.

There was no problem with us using these rooms for now since Sona was still several years away from gaining her Evil Pieces.

There was a small argument caused by Lily wanting to sleep in the same room as me and Lady Sitri saying it wasn't proper until Serafall stepped in and convinced her. She argued that there was no problem given our ages and that, while I may not have this problem, Lily would still be incredibly weary about this new place.

Once Lily had been set to bed, I promised her I would be back soon. Lady Sitri directed us toward Lord Sitri's office.

When we arrived Serafall revealed that they were going to add me to the Sitri magic circle and Lord Sitri, sitting behind his desk gave me an explanation.

Magic circles could be likened to magic calculators. Like how calculators help in problem-solving by doing the calculations for you, magic circles help in magic casting by doing all the tedious magic computations.

But as everyone who's ever done a calculator maths exam knows, even if the calculator can save you from all the long tedious calculations, you still need to figure out what calculations to do and where to apply them on your own.

Similarly, magic circles will do the tedious part of spellcasting but the caster still needs to decide the spell and its parameters like location and size.

Of course, magic circles aren't necessary for devil spell casting they definitely make it more efficient.

In the maths example, casting with a circle is like following the steps to solve a problem, whereas casting without is like randomly guessing an answer before working back to check if it fits and then repeating the process with a new guess when it doesn't; still possible but much more time consuming and exhausting.

Casting without a circle takes more energy, focus, and usually time than with a circle.

This is why all devils, and demons, who can use a magic circle do. Since demonic power is imagination-based, there is an impossibly large number of spells that can be cast resulting in the need for casting assistance. Unlike angels whose power is set to a single element (holy) and typically predisposed to form in the shape of a spear when used offensively.

Even in their magic angels and demons/devils are diametrically opposed.

The Sitri clan's magic circle is specialized slightly towards water element spells to even further boost efficiency when combined with their clan trait, but is also effective at providing assistance to most other spells.

Lord Sitri then summoned the magic circle in question on the palm of his hand and pointed it at me.

The magic circle was deep blue with the Sitri family crest at the center surrounded by many lines crossing and combining with each other to form a complex pattern.

I was told to pass my demonic power into the crest, and whilst I did so Lord Sitri explained that there were three variations of the circle. The master one held by the family head, used to add other members of the family; the heir circle, used to designate the heir of the house and mark the recipient of the Lord's authority in case of untimely death; and the standard circle for every other member of the family.

After pouring in enough power something shifted and the knowledge of the circle appeared in my mind and I gained a deeper understanding. The circle wasn't a spell itself, more like a filter you pass other magic through when casting.

I was able to summon the circle into my hand by pouring some power into it. This was congratulated with a 3 welcome to the Sitri family.

We chatted for a little while more before Serafall said she needed to go and get to work, though not before she gave us all a hug and reminded me that she'd come to get me for a meeting in a few days.

I saw Serafall at the mansion door where she telephoned away. Once alone I quickly found a maid and asked them to guide me to my room so as to not keep Lily waiting long. Although when I arrived she was already asleep.