Blue Grimoire

The Blue Grimoire (蒼の魔道書), also known as the BlazBlue is the so-called "strongest" grimoire, the "original book", and can tap into the power of the Blue.

Information
Despite being called a grimoire, its form is not that of a book, but rather a high-density mass of concentrated magic element similar to the Black Beast. Its original purpose is to utilize the power of the Boundary similarly to a Kiln, and was smelted with the power to oppose the Amaterasu Unit.

It has no fixed form. In case of Ragna, it originally had the form of a jet black rock shaped in the fashion of a human without a head when it was in the possession of Rachel Alucard. After Ragna touched it, it crumbled, turned into a mist, swallowed him in darkness, and then took the form of his right arm, despite still having the same obsidian blackness.

One of the Grimoire's weaknesses is that it will remember the wounds that were dealt to the soul, to the point of transcending even Event Interference. Continuous corrosion of it, might even cause ruptures of other phenomena as well.

Ragna's BlazBlue is remains of the Black Beast and is also fused with the Idea Engine. During the Continuum Shift, one of the probabilistic events was him losing the control over the Grimoire, which absorbed him and turned into the Black Beast, who destroyed almost all of the planet.

According to Litchi's realization, the Blue Grimoire is like the Boundary itself, the Blue surrounded by limitless amounts of magic element.

Activation
Ragna used two different activation codes during the series:

Trivia

 * Ragna's Blue Grimoire is written with kanji 蒼, which means "blue" and "pale", when Hazama's is written with 碧, which means both "blue" and "green".
 * Contrary to popular belief, Nu's eyepatch is not a Blue Grimoire, but a Magic Power Regulator (魔力調節機) to keep magic element absorbed into her body from spinning out of control.
 * Despite this, Nu recites the BlazBlue activation spells during her Astral Heat.