ナハトヴァール 闇の書の闇
The materialisation of the Defense Program of [[tome of the night sky|the Book of Darkness]].
Although the name was first mentioned in [[mahou shoujo lyrical nanoha the movie 2nd a's|The MOVIE 2nd A's]], for convenience, also can used here for the "[b]Darkness of the Book of Darkness[/b]" in [[mahou shoujo lyrical nanoha a's|A's TV version]].

h4. Nachtwal's Forms
* Autonomous Form (基本形)
Multiple purple snakes.
* Equipment Form (装備状態)
An equipment with chain at [[Reinforce]]'s left wrist.
* Armament Form (武装化状態/武装形態)
An [[arm mounted weapon|arm mounted]] [[pile bunker]] known as Spear Cannon (槍射砲).
* Eroded Form: Darkness of the Book of Darkness (浸食暴走体/闇の書の闇)
The final boss in [[mahou shoujo lyrical nanoha a's|A's]] and [[mahou shoujo lyrical nanoha the movie 2nd a's|The MOVIE 2nd A's]].
nachtwal