Erasmus Darkening

Erasmus Darkening is an alien scientist who came to Earth 300 years ago. He posed as a magician and alchemist to Lord Marchwood, using advanced technology to open a portal between dimensions in an effort to get home. Innocent people, caught in Darkening's experiments and trapped between the dimensions, were thought to be ghosts haunting Ashen Hill Manor. (SJA: The Eternity Trap)