The Megans were humanoid in appearance, indistinguishable from Earth humans, although due to their magical abilities, they could take on many forms, such as the form of spirits.
Millenia ago, in their search for companionship, they passed through the point between dimensions and eventually we found ourselves on Earth. Wherever they went, they became advisors to mankind, drawing on the power left behind in their own universe to make it work for Humans.
However, wherever they went, some humans would attempt to use them to gain power and to serve their own greed and lust. When they refused the Humans turned against them and taught other humans to fear and hate them. By the 17th century, those who survived settled in Salem, Massachusetts, attempting to live as "normal men" to avoid the accusations of being "devils, wizards, warlocks and evilsorcerers." Unfortunately, while living in Salem, several of the Megans made mistakes and used their powers. They were burned for doing so, as witches during the Salem witch trials.
Those Megans who escaped the witch trials gathered their power and escaped to their homeworld, where they remained bitter and fearful of Humans.
Much of the history of the Megan visitation to Earth came from either Lucien or Asmodeus, two beings that appeared to hold strong and contradictory oppinions about what had happened.
Several different manifestations were seen of megans, including blue-headed forms, and Satyrs like Lucien which appeared to be distinct. Monster-like spirits were also briefly seen, which one can assume are Megans since there were no other lifeforms in their universe.