Reinforce in her Battle Clothing undersuit
Device profile
Other namesThe Will of the Book of Darkness (pre-reprogram)
The Blessed Wind
Reinforce Eins / Eins
Alicia Testarossa(when impersonating her in the dream world)
MasterHayate Yagami
Magic systemAncient Belka
HandlingAuxiliary control
Humanoid Device profile
Ageuncertain, but at least several centuries
HomeworldOld Belka
Date of death0065
FamilyYagami family
Magic colorPurplish black
White (in A's ep.13)
DeviceBook of Darkness (the Book) (pre-reprogram)
Japanese nameリインフォース
First app.A's manga (ch.3, as the Will of the Book of Darkness)
A's (ep.10)
Last app.A's (ep.13)
Voiced bySanae Kobayashi

Reinforce (リインフォース Ri'infōsu) is the Master Program of the namesake Unison Device. She is originally the nameless Master Program of the Book of Darkness (known as Tome of the Night Sky in Ancient Belkan era before corruption), a Lost Logia and an intelligent creation of Belkan mages whose names have been lost to time. The Book's final master Hayate Yagami has reprogrammed the Unison Device and "gifted" this Master Program a new name, i.e. Reinforce.


Presumably, Reinforce was named after a battleship from Victory Gundam, which was destroyed and rebuilt as the smaller "Reinforce Jr.".

Prior to the reprogramming by Hayate, the nameless Master Program is referred to as "the Will of the Book of Darkness" (闇の書の意志 Yami no Sho no Ishi). When she takes over Hayate in a Reverse Unison, Nanoha Takamachi has called her Ms. Book of Darkness (闇の書さん Yami no Sho san). She also addresses herself as "the Tome" in The MOVIE 2nd A's.

Upon reprogramming, in addition to giving her a new name, Hayate also titles her as "the Blessed Wind" (祝福の風 Shukufuku no Kaze).

In Reinforce's scenario in The Battle of Aces, she refers to herself for the first time as "Eins" ((アインス) Ainsu, German for "one"), urging Hayate to reserve the name "Reinforce" for her future Device, foreshadowing the naming of Reinforce Zwei. Since then, Vita and Hayate have also referred to her as Eins (初代(アインス) Ainsu, lit. "first generation") in ViVid ch.ex and Force ch.18 respectively. In the 12th TVCM of The MOVIE 2nd A's (a cross-continuity ad), Reinforce also introduces herself as "Reinforce Eins" (リインフォースⅠ Ri'infōsu Ainsu).

In A'sEdit

Chr 232

Hayate Yagami taken over by The Will of the Book of Darkness

Reinforce appears, simply as the "Book of Darkness", in the A's manga. Although she cannot communicate with her master, she can control the Book to float around her house and interact with Hayate physically in a manner reminiscent of a pet. Her inner monologue, however, reveals that she is fully aware of herself and their situation but cannot manifest herself in any other way until her pages are filled up.

When all the pages of the Book are filled the Will of the Book of Darkness takes over Hayate's body transforming it into an approximation of herself and attempts to avenge the Wolkenritter and once it's clear that the Masked Men impersonating Nanoha Takamachi and Fate Testarossa aren't present while using the two's appearance and that the Defense Program has begun it's rampage; trap all of earth's inhabitants in the Dream of the Book of Darkness before the Defense Program fully takes over.

The Will of the Book of Darkness first traps Fate in the Dream then goes after Nanoha and manages to come out unscathed from Nanoha's Exelion Buster A.C.S despite it going past her shield.

Hayate, while placed inside a void in the Book's separate dimension, opens her eyes after presumably being asleep, but the Book tells her to go back to sleep and escape the tragic reality. She refuses, and instead orders the Will of the Book of Darkness to cease all attempts to trap Earth's inhabitants in an eternal dream.

Following this order the Will of the Book of Darkness using Alicia Testarossa's form returns Bardiche to Fate so that she may escape from the Dream of the Book of Darkness before telling her that she wished for the dream's world in real life as well.

While this is happening the Defense Program seizes control of Hayate's transformed body causing the Will of the Book of Darkness's irises to disappear from said body's red eys(though not from the Will of the Book of Darkness herself). Just as the Defense Program has Nanoha cornered, Hayate disrupts the Defense Program's defenses so that Nanoha can disable it. During this process, Hayate gives the Book of Darkness a new name: "Reinforce".

Hayate reprograms the entire Device removing the Defense Program. Reinforce accepts her new name as Administrator's Rights are given to Hayate thus allowing Reinforce to become her partner. The reprogrammed Unison Device comprises Reinforce the Master Program, the Book and the Staff. (See Book of Darkness for more information.)

Reinforce tells Hayate that without an intelligence the Defense Program will enter a mindless rampage only for Hayate to tell her that they got to stop it then.

The characters involved in the incident from both the Administrative Bureau meet up with the Wolkenritter, who are then reformed by Hayate. Reinforce and Hayate perform a Unison, and the group teams up to defeat the Defense Program.

In the aftermath of the battle, Reinforce believes that she has to be destroyed for the viral Defense System to never to return, and convinces Nanoha and Fate to do so. Hayate, however refuses to let her go. After persuading Hayate to her side, Reinforce asks her one request: to preserve the title of "the Blessed Wind" for the new container in the future, stating that she will always be with Hayate through the Knights and the new container. Reinforce then self-destructs, with only the Schwertkreuz-like fragment left over.

Reinforce makes a cameo appearance in a flashback in the final chapter of A's manga, when Nanoha suggests that her personality has melded with Hayate's.

In an epilogue that bridges the gap between A's and StrikerS, Reinforce is revealed to have been the main inspiration for Reinforce Zwei. She is much smaller than her predecessor but still allows the normal functions of a Unison Device.

In ForceEdit

Reinforce (as the will of the Book of Darkness) only appears briefly in the prologue of Force, in a flashback of the Ancient Belkan era.

Alternate continuitiesEdit


Reinforce mainly appears in The MOVIE 2nd A's. During the roadshow of Reflection, Reinforce also makes a cameo appearance in the fourth bonus weekly movie at the end, having a conversation with Yuri therein.

In The MOVIE 2nd A's, she is not referred to as the Master Program of the Book of Darkness, but instead appears as a regular Unison Device. She seems to retain complete consciousness, rather than being driven by NachtWal, i.e. the Defense Program. In fact, she also equips it on her left arm as a weapon when she can still exercise control over it.


Reinforce appears as a playable character in both Battle of Aces and Gears of Destiny. In fact, the point of divergence of this continuity is the refusal of Nanoha and Fate to help destructing her (as they do in A's ep.13) with Hayate instead tearing out the data of the Defense Program from the Tome of the Night Sky's Core to prevent the book from reviving the Defense Program and as a result reducing Reinforce to a state where she can't Unison and slowly degrades till her body(and possibly mind) is destroyed while the torn out data becomes Dark Fragments that have begun reviving the Book of Darkness separate from the Tome of the Night Sky as well as it's Defense System in the form of the Materials.

In her path of Battle of the Aces she encounters a new Will of the Book of Darkness revived from the Dark Fragments who tells Reinforce that the curse of the Book of Darkness cannot be stopped and Reinforce should just return to her. Reinforce refuses and destroys the new Will of the Book of Darkness who in her last breath informs Reinforce that the Materials will not end with her(revealing Reinforce and thus the New Will of the Book of Darkness as Materials themselves) as the Core Material of the Automatic Defense Program still exists and will continue to make Dark Fragments.

In The Gears of Destiny, Thoma Avenir and Lily-Strosek, as time-travelled from 0082, mistaken her as "Teacher Rein" (リイン師匠 Ri'in Shishō), i.e. Reinforce Zwei.

Later during the final battle against U-D Reinforce preforms a Unison with Hayate even though she is in no state to do so and as a result(according to The Gears of Destiny Sound Stage A) after the battle following the Florian Sisters' return to the future taking the Purple Sky Family with them she loses consciousness and her body is destroyed leaving her unconscious within the Tome of the Night Sky(which has been reduced to a Storage Device) with no word on whether she can be recovered in this state.

Brave DuelEdit

Reinforce Eins Yagami (八神リインフォース・アインス Yagami Ri'infōsu Ainsu) is a shop assistant of Yagamido, along Signum Yagami and Shamal Yagami.


Like the Wolkenritter and many other mages, she is capable of flight and telepathy. Her magic color is black with purplish aura and becomes Hayate's white color when performing the self-destruction magic by the end of A's. However, it does not change but remains purplish black in the portable continuity.

Her magical ability is area-of-effect attack, which even enables her to re-arrange spells for wider area effect. She also possesses the Rare Skill Use of Collection and hence has access to all spells stored in the Book of Darkness through Linker Core absorption. Such spells generally use their original casters' magic circle and magic color, despite the magic color may change to hers when she cast a re-arranged variation (e.g. Photon Lancer Genocide Shift). Notably, when casting Nanoha's Starlight Breaker, she adds an aria to the spell which Nanoha has never been seen to use.

Battle ClothingEdit

Reinforce does not cast Knight Armor but Battle Clothing as her protective clothing.[1] Its undersuit takes the form of a plain black minidress with a gold band around her waist, two more crossing over her chest, and a red belt around her neck. She wears fingerless gloves, and armoured black boots with socks of two different lengths. The same black minidress is worn by Signum as non-combat attire before she receives casual clothes from Hayate. In combat, she adds a blue-black jacket and a blue-black skirt with gold trim similar to Signum's Knight Clothing(the new Will of the Book of Darkness in Battle of the Aces wears purple-black with a gold trim instead), along with two pairs of raven-like wings from Sleipnir spell.

While under the influence of the corrupted Defense Program before reprogramming, she has red lines on her Reverse Unison form's skin, a small pair of wings on her head, and red cords wrapped around her right arm and the exposed skin on her legs. The first two traits are shown by the Defense Program itself when it is separated from Reinforce. None of these traits are shown by Reinforce within the Book itself.

Knight ClothingEdit

Exclusively in The MOVIE 2nd A's, Reinforce casts Knight Clothing after being reprogrammed. Its design conforms to Hayate's Knight Armor, which is also set by Reinforce.[2]


AbsorptionAncient BelkaForce fieldCircle
Bind BreakMidchilda
Ancient Belka
Black LanceAncient BelkaAttackArea-of-effect
Bloody DaggerAncient BelkaAttackShootingAAA
Chain BindMidchildaCaptureBind
Diabolic EmissionAncient BelkaAttackArea-of-effectS−
Dream of the Book of DarknessAncient BelkaIllusion
Gefängnis der MagieAncient BelkaForce fieldArea
Lightning BindMidchilda
Special (IS)
PanzerschildAncient BelkaDefenseShield
Photon Lancer Genocide ShiftMidchildaAttackShooting
Restrict LockMidchildaCaptureBind
Scarlet Dragon SummonMidchildaSummoning
Schwarze WirkungAncient BelkaAttackMagic-enhanced attack
SleipnirAncient BelkaSupportTransport
Starlight BreakerMidchildaAttackBombardmentS
Thunder of the Night SkyAncient BelkaAttackArea-of-effect
Use of CollectionAncient BelkaRare Skill

In the gamesEdit

Spells in The Battle of Aces

Cross Range Long Range Long Range (Charged)
Attack/Basic[unnamed]Bloody Dagger
Block/HighDark WeaveNightmareHowling Sphere
Catch/BindSchwarze WirkungSeal Bind
LFDBThunder of the Night Sky---
Spells in The Gears of Destiny

Cross Range Long Range Long Range (Charged)
Attack/Basic[unnamed]Bloody Dagger
Block/HighDark Weave (?)NightmareHowling Sphere
Catch/BindSchwarze WirkungSeal Bind
△△EX Attack[unnamed]---
LFDBThunder of the Night Sky---



  1. ^ Magical Girl Lyrical Nanoha A's Portable: The Gears of Destiny.
  2. ^ MGLN The MOVIE 2nd A's Official Guide Book, pages 10 and 16.