intrigant

/ˈɪntrɪɡənt/
noun
  1. A person who makes secret plans to harm others or gain power.
    • In the royal court, an intrigant spread rumors to turn the king against his advisor.
    • The journalist exposed the political intrigant who had been bribing officials for years.
    • The novel's villain is a cunning intrigant who manipulates everyone around him.