Item from Mahou Shoujo Lyrical Nanoha by Masaki Tsuzuki / Seven Arcs
An ancient Lost Logia that began as the Tome of the Night Sky — a benign magical storage medium — and became a parasitic grimoire after tampering that corrupted its Defense Program, killing its masters for centuries.
The Book of Darkness was originally the Tome of the Night Sky. Curious mages trying to seal away another artifact corrupted its Defense Program, and it became parasitic — slowly killing its masters unless they filled its 666 pages with mana from stolen Linker Cores, at which point the Defense Program would kill them anyway and begin again. Hayate found it in a library while in her wheelchair. She thought it was interesting. It started killing her immediately. She named it. She gave it to Reinforce as a name. This is who Hayate is. At the end of A's it was fully reprogrammed and the Defense Program permanently destroyed. Hayate later recreated the Tome of the Night Sky as a new, clean Storage Device based on the original's design. The franchise distinguishes carefully between the two.
A large leather-bound tome in chains, sitting on Hayate's bookshelf where she found it. It pulses with dark power. In activated state it's a significant presence — the Master Program can manifest as a humanoid figure, the Wolkenritter emerge from it, the Defense Program is something architectural in scale.
Also known as: Buch der Dunkelheit, Tome of the Night Sky, Book