Evil-Lyn is a henchwoman to Skeletor (Frank Langella) and spends most of the film trying to retrieve a "cosmic key" which has ended up on Earth in the hands of a teenager, Kevin Corrigan (Robert Duncan McNeill), who thinks it's a synthesizer. Later a cop, Lubic (James Tokan), takes the key from Kevin believing it to be stolen. Then Evil-Lyn shows up and has an interrogation collar put on Kevin, which forces him to tell the truth, revealing that Lubic has the key. Evil-Lyn successfully recovers the key, summons Skeletor and they take He-Man (Dolph Lundgren) back to Eternia as a prisoner. Evil-Lyn deserts Skeletor after he absorbs the "Power of the Universe" without sharing it with her.
Evil-Lyn is wearing knee-length leather boots, lavender catsuit, shiny metal breastplate and vambraces, and elaborate jewelled crown. Meg Foster's scary blue eyes add to the characters menace quite well. She is depicted as a powerful magic-wielder, but she rarely uses magic in the film except when she casts illusions.