Definition of evil genius in English:

evil genius

noun

  • 1A malevolent spirit imagined as accompanying a person and seeking to influence him or her to do evil, and often paired with an opposed benevolent spirit; (in extended use) a person who exerts an evil influence; compare "genius", "malus genius".

  • 2A person with an exceptional capacity for wrongdoing or malevolence.

Origin

Late 17th century; earliest use found in Afra Behn (?1640–1689), writer.