Sankishin

The Sankishin (the three sacred treasures), also known as the Original Units, served as the inspiration for the Nox Nyctores, though little else is known about them.

Amaterasu Unit
The Amaterasu Unit, also known as the Master Unit. It lies hidden within the Boundary and can only be found by the true possessor of the Azure Grimoire. It's named after Amaterasu, the Sun Goddess.

Susanoo Unit
The Susanoo Unit, owned by Hakumen, who also wields a Nox Nyctores, implying that he has extraordinary strength. Its full capacity is unknown, though it seems that Hakumen's soul is bound to it; when Jin Kisaragi was on the verge of death, Rachel Alucard installed him into the Unit. Because he was not fully salvaged from the Edge, he's apparently operating at only about 20% of his full capacity. It's named after Susanoo, the Storm God.

Tsukuyomi Unit
The Tsukuyomi Unit, owned by Rachel Alucard. It's described as an ultimate defense and resembles a giant golden shield. It's named after Tsukuyomi, the Moon God.