Using a combination of science and magic, Dr. Oonagh Mullarkey split the good and evil parts of her personality in an attempt to gain more power.  Originally placed into a lifeless protoplasm, the good half developed into the life form Plasmer, a shape-shifting superhero - while the evil half remained in Dr. Mullarkey.
 
Plasmer would eventually journey alone on a path of self-discovery, where she would meet Jack Smithers.  He would reveal her evil was attempting to unleash a group of Sleepers in an attempt to destroy the world.  With the help of her allies, including the Silver Surfer, Plasmer would defeat all the Sleepers.