Susano'o Unit

"Be the white void. Be the cold steel. Be the just sword. Take blade in hand to reap the sins of this world and cleanse it in the fires of destruction."

The Susano'o Unit (スサノオユニット) is one of the three Sankishin, and cuts time. It is unique in that it grew a soul that became known as Yuuki Terumi. The Unit has had many owners at various points, but was most notably wielded by Hakumen.

Information
The Susano'o Unit has existed for an unknown amount of time, and was originally within the Boundary. At some point, it developed a soul, a consciousness that was sick of its existence being tied to destroying the creations of the Amaterasu Unit. Susano'o allowed himself to be found by humanity, and was the catalyst for the creation of the Prime Field Devices and the Prime Field War.

The soul within Susano'o grew sick of its body, and separated its soul from it, becoming known as Yuuki Terumi. The Susano'o Unit was left behind, and was claimed by Clavis Alucard before being stored within the Alucard Castle. Just before the Dark War began, Clavis and his daughter Rachel Alucard, gave the unit to a version of Jin Kisaragi that had fallen backwards through time. He became known as Hakumen, and wielded it throughout the Dark War before being sealed within the Boundary.

Kokonoe recovered Hakumen using science and Observed him, but the Susano'o Unit was only within 20% of its original power. Terumi eventually took his body back using the Hihiirokane, becoming Susano'o once again. He was killed by Ragna the Bloodedge and the Susano'o Unit was sealed in the Boundary by Trinity Glassfille. Hakumen's soul is still within the Unit.

The Susano'o Unit grants incredible strength to its user, making them far stronger than they would usually be. It can also be wielded in conjunction with other weapons, such as the Nox Nyctores - Interfectum Malus: Ookami and the Hihiirokane. When a wielder is within the unit, they are protected completely from the seithr within the Boundary, allowing them to survive its influence. It appears that the Unit's influence can change the wielder's personality. Hakumen became far more serious and focused while using it, while Susano'o was given an irresistible urge to destroy everything. It also appears to have a form of sentience as it communicated to Hakumen before he became its wielder.

The Susano'o Unit takes the form of a large set of armor that normally stands 208cm, but rises to 218cm when used by Susano'o. By default, it is a white set of armor with a blank mask, long silver hair, multiple red eyes, and black thighs. Its plate near the clavicle is comprised of the mythical alloy, hihiirokane. When used by Susano'o, the unit not only rises in height, but it becomes completely black with multiple green veins running along its surface. The once silver hair becomes black and dishevelled, while the blank mask grows a row of sharp teeth.

Wielders

 * Susano'o/Yuuki Terumi - original soul of the unit; deceased
 * Hakumen - wielded throughout the Dark War
 * Jin Kisaragi - wielded briefly with aide from Trinity Glassfille

Etymology
Susano'o-no-Mikoto is the Shinto God of the seas, and one of the most important deities in the religion. He is the son of Izanagi-no-Mikoto and the brother of both Amaterasu-no-Mikoto and Tsukuyomi-no-Mikoto. Susano'o is credited as being as violent and unpredictable as the seas he rules over, and had a feud with Amaterasu which caused his expulsion from Takamagahara. He slew the Orochi, a serpent with seven heads during his exile, mirroring Hakumen's defeat of the Black Beast.