Book of the Blue Blaze

The is the true Blue, and also the true BlazBlue.

Information
Hades: Izanami initially was setting her sights on the said Book, but in the end it was obtained by Ragna the Bloodedge after he killed Yūki Terumi in the end of BlazBlue: Centralfiction, when the two of them were summoned into the Boundary Line of the Blue after the Forbidden Gate was opened.

Ragna used the Book to rewrite his world, erasing his existence from it as well as restoring everyone who turned into magic element during the Doomsday by the Embryo.

Both the Blue Grimoire and Hazama's body being the Bleu Grimoire are fake/prototype versions of the Book, created by Terumi when he managed obtain a small sample of the Blue itself. Despite its name, it is not a book, but instead a concentrated mass of power.