With the opening of the Shadowlands, the history of
the Medusae has begun to clarify. The Medusae, like the
Enigmae, are creations of the Xan, a manipulation of
humanoid genetics and those of other species and races.
It is unclear what the original intent of creating this
race of powerful females was, but the abundance of them
throughout the Shadowlands, and their proximity to the
extremes of Rubi-Ka, would tend to dictate that the have
prevailed throughout the Shadowlands for an extremely
long time, and only became capable of crossing to
Rubi-Ka after the dimensional rifts stabilized with the
terraforming of Rubi-Ka.