Seithr Regulator

A Seithr Regulator (魔力調節器 Maryoku Chōsetsu-ki) is a device which moderates the amount of seithr that its wielder uses. These regulators prevents the seithr from their user's bodies from going out of control.

When Ragna the Bloodedge activates his Azure Grimoire, the seithr regulator on his right arm opens, allowing him to access its full power.

Wielders

 * Ragna the Bloodedge - visible on the backs of both his hands
 * Nu-13 - visible as her eyepatch on her right eye. Has two more on her back when using the Lux Sanctus: Murakumo
 * Mu-12 - visible on her pauldrons
 * Izayoi - visible on her lower back
 * Kuon Glamred Stroheim - visible on the back of her head in her Code: Embryo outfit