Witches 5, out to get Sakura Xadium Aino
Human? Possibly a Diamon in a human host.
Science and Engineering
Eudial was, in life, a highly skilled scientist in the vein of her mentor, Professor Tomoe. As part of the Witches 5, she had a rivalry with Mimette.
Many many years from now
After Eudial's defeat at the hands of the Sailor Senshi in the early-mid 1990s on Earth, she somehow crawled her way back to the land of the living and began making a name for herself in the criminal underworld brought about by human and alien interactions. The Scientist's skills were unrivaled by any others in her line of work, and all of them were for sale to the highest bidder. This evil-go-lucky lifestyle came to an abrupt end when Eudial's attempt to fix the results of the 2395 Alpha Quadrant playoffs, in which the sport of baseball was making a resurgence, was thwarted by Sakura Xadium Aino.
Completely taken aback by how easily her scheme had been thwarted, Eudial's murderous fury was only whetted when she discovered that her enemy was a time-traveling child. Eudial considered her revenge complete after setting a trap that would not only kill Sakura, but her mother and father as well—and as far as Eudial could tell, her revenge was complete and she subsequently returned to the life of an evil genius.