Character from Mahou Shoujo Lyrical Nanoha by Masaki Tsuzuki / Seven Arcs
The Master Program of the Book of Darkness — a nameless intelligence who watched from inside a cursed grimoire for centuries, was freed and named by Hayate, and then destroyed herself so the Defense Program could never return.
Reinforce was fully aware inside the Book for its entire history. She could hear everything, process everything, and communicate only in limited ways until the pages filled. When Hayate reached her and reprogrammed the Book, she was given a name and became Hayate's partner. The tragedy is that she already knew what had to happen. The Defense Program could be destroyed but not permanently — it would regenerate within days. The only way to prevent that regeneration was to destroy the root it grew from, which was her. She convinced Hayate to let her go. This took most of A's final episode. She is not the same as Reinforce Zwei (Rein), who is a new, smaller Unison Device Hayate created afterward. Rein is Reinforce's successor, named with the same love. Reinforce is gone. The franchise does not soften this.
A humanoid figure with long silver-white hair, wearing battle clothing in purplish-black that shifts to white in the moments before her self-destruction. She looks like something ancient and precise, which she is. Her magic is purplish-black becoming white.
Also known as: Reinforce Eins, The Blessed Wind, Will of the Book of Darkness