OK, So I just finished all the endings and 100%-ed every characters story. Holy man, the story for this game is confusing.  
 
What I am wondering is the whole thing between Hakumen and Jin - how are they the same person? I realize that Yukianesa is making Jin crazy in the same way Bolverk makes Noel brave and how Nirvana makes Carl delusional. But then how is Jin somehow Hakumen? In Hakumen's story, when you beat Ragna, he will take off his mask (but not show the screen) and Ragna and Hakumen call each other brothers, numerous times. In the credits, Hakumen's voice actor was blanked out but when you beat the true ending you see that it's the same voice actor as Jin's. Then when you have to beat Jin as Hakumen, he calls Jin an apparition. This was such a surprise to me, one of the few Videogame plot elements that I have never seen through. Usually I can figure games out before they end, but man...  
 
Oh yeah, And I'm wondering about the Six Heroes - I know that they were Nirvana, Nine, Hakumen, Valkenhyn, Jubei and Terumi. Why did Terumi turn evil? How was Nirvana able to support herself without an owner? What's Valkenhyn's deal... why is he now a butler for a family of vampires? Surely Rachel's father must have played an important role back then. 
 
And one more thing... I read on another board that Carl's Father, who was an alchemist, found Nirvana and incorporated his daughter and Carl's sister, Ada, into it. I'm not sure why though, maybe her body was failing or something. That's why Carl is thinking he can bring his Sister back.
 
Also... what are the known Nox Nyctores? I know that Jin has Yukianesa, Rachel has Tsukuyomi, Hakumen has either his sword Ookami or his Susano'o suit, v-13 has her Murakumo Unit, Carl has Nirvana, Noel has Bolverk, Litchi has Lau Jiu (the panda in her hair)... and that's it I think?