Sisters of silence
The Sisters of Silence, also known as the Anathema Pskyana or Silent Sisterhood, are an ancient, anti-psychic militant order. They are the militant arm of the Adeptus Astra Telepathica and are internally referred to as the organization’s Departmento Investigates. However their affiliation with this body is largely symbolic, and in truth they are an autonomous military force answering directly to the Emperor and the Lord Commander of the Imperium. Together with the Adeptus Custodes they represented the Talons of the Emperor being the left hand of the Emperor. Fragmenting after the Horus Heresy, they were brought back under Imperial control by Roboute Guilliman in M41. Its ranks consist entirely of Blanks.