So, Ragna carries this 'Blood Scythe'... it has something to do with the Black Beast?
Does this book mentions about the fake Azure? Did Terumi gave it to Ragna (he mentions if his 'fake' arm was helpful during true ending scenario)?
Regarding the Black Beast, It still unclear to me, after having watched several story mode endings:
Tager: after fighting Arakune, the Black Beast emerges from underground;
Ragna: after fighting 'himself', loses control of himself and turns into the Black Beast;
Carl: after 'Strange Space', Nu & Ragna fuses, and the black beast emerges;
These events shows the Black Beast during the present, correct?
At that moment, were the characters drawn to the Boundary along with the Fusion and therefore were destroyed by the black beast in the past? Or the black beast warps the present before going to the 'past' via the boundary?
Regarding the Six Heroes, Valkenhayn were the 'bell carrier'?
Terumi was always a ghost or did he turned into a ghost after the Dark War?
I concluded that Terumi possessed Jin during the church attack (his trademark 'smile is show during the beginning of Ragna's story mode), but not against Jin's will, Jin wished for Saya's death to stay with his brother.
Suzaku, it is still unclear to me, after compiling all pieces of information, if Hakumen was killed by Ragna during True Ending Scenario.
We may consider it to be Bang's, since he carries a Nox Nyctores as well (as stated by Rachel during her story mode). In one of his moves he yells something like 'Phoenix' in the air, I can't say for sure.
Are there more than 10 Nox in existence, or the book mentions that only 10 nox are known up 'till the current timeline?
I disagree, Nine was killed by Terumi as it is stated on the book (thank you for translating Suzaku). I concluded that Nine & Jubei knew about the time loops, Hakumen (Jin) may have hinted something for them (even Valkenhayn, if he exists out of the loop along with Rachel). I also believe when Jin was sent back through time via the Boundary, he retained his original memories (received from Yukianesa) for a while after wearing the Susanoo Unit.
Time passed and his memory strained, he remember only fragments of his past (as shown in his story mode during one path). Hakumen only knew that Ragna is 'the source of all evil'. I believe Jin/Hakumen always loved Ragna, in spite of being selfish in the past.
Isn't it strange that Nine and her sister babied the three siblings during their childhood just by coincidence? When Nine and her sister were killed (it means the original plan failed), Jubei arised (as contingence) to be Ragna's mentor (Rachel was a part of the equation, she had to bit him in every loop) in order to prevent the Calamity Trigger to happen again, so Ragna could carry on by his own strength.
I think their conversation (Jubei & Ragna's) during True Ending confirms this assumption.
One more thing is that Terumi did want to break the loop, at least I felt like his intentions could lead to that. But only in a sequel we will know his true motives.
I'll edit more this post as soon I have the time.
Regards!