From SuspireWiki

In domains where there are large numbers of Acoyltes the Hierophant of the Circle of the Crone may appoint a Vala. The position of a Vala can differ from domain to domain depending on how involved the Hierophant is. The Vala may serve as the Acolyte who performs all rituals or as an advisor to the local Acolytes or even as the Acolyte who studies and researches for the Hierophant.

Vala are also known as Apex, Low Priest, Witch or Warlock.