Like the mythical hydra, the Illuminati have many heads and even more hands. The minions of the Illuminati might work to their hidden master's ends without ever knowing the design of their work, or for whom they indeed work for.
A golden skull contains the spirit of a person who has been magically entrapped in an ethereal undead status by an ancient ritual. The person was boiled alive in a golden mixture until nothing remained of him except the bones, now covered by a golden layer. Whoever has these golden bones, controls the spirit and can command it. It can assault the living with wind and storm. Manipulate objects and communicate with the living. (Inspired by Anne Rice, Servant of the Bones)