
Barbas (Marbas), also known as the Demon of Fear, is described in the Ars Goetia as a Great President of Hell governing thirty-six legions of demons. His primary power is reading the fears of his victims and using those fears against them. Barbas was originally bound to a cycle which only allowed him to return to earth every thirteen hundred years. This cycle could only be ended if he killed thirteen unmarried witches on Friday the 13th.