The Sibylline Sisterhood were a women-only cult active in ancient Pompeii, members of which breathed in Pyrovile Dust which granted them their supernatural abilities but also slowly converted them into stone Pyrovile. many if not all of the cultist seemed to posses the power of foresight, which could be explained by the Temporal rift that was briefly created by the power of the Volcano, and they could also communicatie telepathicaly.
Membership of the sisterhood was seen as prestigious by Pompeii inhabitants, and the Caecilius family had pledged their daughter to the sisterhood for life.The organisation had existed for generations, but presumably ceased to exist when the Vesuvius exploded, destroying the entire city of Pompeii.
Their leader is the High Priestess and known members are Soothsayer, Spurrina, Evelina and various other women.
The Sisterhood was the cult itself, the soothsayers were known as the Sibylline Oracles. (DW: The Fires of Pompeii)
