Answers

Vergil is 13 y/o right now because the school system in Jap pretty much confused me so the system I'll use is 6 years in elementary school, 3 years in middle school, 3 years in jr. High, 3 years in senior High. Meaning by the time Mc reached 3rd year in senior highschool, he'll be of legal age. (I only know that school system like this was used so that when students graduated from HighSchool, they can immediately go to work legally.) Also I've read that men can marry in Japan when they are 18(With parental consent, 20 if without.) while girls can marry for as young as 16. If you prefer the school system like this, let me know. Also the cannon would start in their 2nd year in senior high(where the school goes co-ed) which I will breeze through with another timeskip.

Also my stance with Rias is neutral, I don't like her but I also don't hate her. Well, think about it, if you are in a forced marriage with a person known for his r*ping tendencies, would you still go through it? It made her desperate that's why she needs every little thing she can use to prevent it from happening. What I don't like about her is her spoiled brat attitude, she wants to break the engagement but she doesn't train a single bit. As for Akeno and Koneko, as I've always said, It doesn't matter where they are or in whatever peerage they may be, because Yamato can always split the person from the piece and also, due to Grayfia's stunt Akeno is not a loyal queen for Rias. I'll explain why Koneko is in the gremory peerage next chapter.

Also Dante is using firearms in his mercenary days. He keeps using pistols like they are machine guns and brings it back to Nell burnt or destroyed to be fixed that's why Nell was mad at dante for it and before she died(Vergil killed her), she gave Dante her final creation, Ebony and Ivory.

As for the note that Akeno received i'll reveal it next chap. Let me know what to improve in the future chaps. Also I don't think I'll be able to post a chapter today because I'm a nanny for my cousins XD but I will still try. No promises. Promises are meant to be broken after all. XD

Good day/night y'all