Evil Jessica is the possesed form of Jessica by the scepter of Rhapthorne in Dragon Quest VIII. Once transformed, she wasn't herself and tried her best to get rid of the descendant of the Seven Sages, which at first the heroes thought she was talking about the magician, Dominico. In an attempt to retaliate, he conjured a magical barrier around him and David, his assistant. Dominico, however did not want him to interfere and he pushed him aside, Rhapthorne's magic grew stronger still and Jessica was able to cause a major riot in the town, David, not following his master's orders went to ace her but it was then that she revealed that David was the descendant. The heroes put a stopped her before she could carry out Rhapthorne's desires.
Besides her regular spells, Evil Jessica is also able to summon Shadows to fight for her.