Unison Device (ユニゾンデバイス Yunizon Debaisu), also known as a "Unity-Type Device" (融合型デバイス Yūgōgata Debaisu) or a "Unity Knight" (融合騎 Yūgō Ki), is a Device form developed only by Belka that has taken the design ideology of Artificial Intelligence to extremes (c/w Midchildan Intelligent Devices). Unison Devices possess their own wills and, given a complete human form and sentience, can "unite" (that is, physically merge) with their masters to provide mana control and assistance according to circumstances.
Unison Devices vastly outperform other types of Devices in response speed and in the volume of mana handled; however, users suitable for Unison (referred to as "Lords", regardless of their gender) are rare, and much work is required to fine-tune and ensure compatibility of each specific user. Furthermore, since Unison Devices can cause loss of consciousness and other effects during Unison, they have emergency countermeasures set up that are not dependent on the Lord's awareness, allowing even solitary users to employ these Devices, enhancing mana usage. However, at times, a Unison Device may "take over" the user and operate autonomously, causing a "Unison accident" (融合事故 Yūgō jiko), therefore such Devices have never been manufactured in large numbers.
During a successful Unison, striking hair or pupil color changes become apparent, and it will sometimes even change the color of the Knight Armor/Clothing the Lord is wearing at the time. However, whether the appearance after Unison is more similar to the Lord or the Device depends on whether the Lord can manage the Device. In the event that a Lord cannot handle it, he or she will lose all control and completely take on the appearance of the Device.
During a Unison, the Lord can always initiate telepathic contact with his or her Device. However, in the case that the Lord loses consciousness or the Device for any other reason has to assume full control over their shared body, it creates a so-called "Internal Space" (内部空間 Naibu Kūkan, likely a pocket dimension), where its master can communicate with it in safety and even recuperate.
In The Battle of Aces (near the end of Reinforce's storyline), Hayate Yagami somehow trades roles with Reinforce and becomes her "Unison Device" of sorts, boosting the power of Unison Reinforce to gargantuan levels. As it is merely referred to by Hayate as a "hidden skill of the Unison system" (融合システムの裏技 yūgō shisutemu no urawaza) and not given a canonical term in the series, it is commonly referred to as a "Reverse Unison" (逆ユニゾン Gyaku Yunizon). Since The Battle of Aces is set in an alternate continuity, however, it is unclear if such Reverse Unison could be properly performed without accident in the primary continuity.
A distinct trait of Unison Devices that sets them apart from other Device types seems to be that they possess their own Linker Cores, allowing them to cast spells of their own (instead of just tapping into their master's mana). For the same reason, Unison Devices can be graded on the mage rank scale and even use Devices of their own (e.g. Reinforce Zwei's Book of the Azure Sky).
Like Familiars, Unison Devices can conserve energy by reducing their size, usually staying at about a foot in height (unlike familiars, their apparent age and build do not change). The original Reinforce has never displayed this ability outside of The Movie 2nd A's, during and shortly before the battle with NachtWal - presumably she is capable of it in any timeline, but her enormous mana capacity generally render it unnecessary.
Known Unison DevicesEdit
"Lord" is the title of a knight who is the master of a Unison Device. In a more general sense, it can refer to any practitioner who is suited for Unison.
|Name||Magic system||Mage rank|
|Zest Grangeitz||Ancient Belka||S+ (Air)|
|Signum||Ancient Belka||S− (Air)|
|Vita||Ancient Belka||AAA+ (Air)|
|Hayate Yagami||Ancient Belka||SS (Synthetic)|
- ^ a b Magical Girl Lyrical Nanoha A's, DVD Vol.4 Booklet, Magic Dictionary (translation).
- ^ Magical Girl Lyrical Nanoha A's, DVD Vol.5 Booklet, Magic Dictionary (translation).
- ^ Magical Girl Lyrical Nanoha StrikerS Sound Stage 03, track 8. Hayate: "My Linker Core is melded with the original Reinforce, and Rein's Linker Core is born from my own Core..."
- ^ Reinforce Zwei appears at normal human size in StrikerS Sound Stage 01, and Agito does so in ViVid chapter 16.
- Unison Device on the Japanese Nanoha wiki