I have a group of mystical being known as the Elementals. There is Geo (Earth, the brick), Pyre (Fire, energy projector), Whelm (Water, energy projector/shape shifter) and Mariah (Air, invisible energy projector) all lead by Void.
He looks like a human-sized-black-hole, he makes no sound, and communicates by telepathy. He has mental powers, some drains useable at range, draining Damage shield, and all of his powers affect the real world when he is desolid. He does have a vulnerability, only none of the players know for sure what it is yet ::evil smirk::
He scares the spit out of my players.