Voodoo

Voodoo (also spelled Vodun, Vodon, Vodoun, Vodou, Voudou) indicates a series of similar and interrelated religions originating in West Africa and spread into Central America and southern U.S., along with the Atlantic slave trade.

Description
Voodoo is an often sincretic religion, combining the system of spirits originating in West Africa with the Catholic hyerarchy of angels and saints, and the concept of a single world creator in both original religions. Worship, including worship to ancestors, is often mediated by initiates, if not full priests, under the name of Houngan and Mambo.

Death Masks
In Death Masks, Harry Dresden summons Ulsharavas, a spirit allied to the Loa, for informations on the location of the Shroud of Turin.