diabolical

/ˌdaɪəˈbɑlɪkəl/
adjective
  1. Extremely evil or cruel; like the devil.
    • The movie's diabolical antagonist was both terrifying and fascinating.
    • He had a diabolical laugh that made everyone in the room uncomfortable.
    • The villain's diabolical scheme involved poisoning the city's water supply.
  2. Very clever in a harmful or mischievous way; fiendishly ingenious.
    • The escape room had a diabolical design that stumped even the smartest players.
    • The puzzle was diabolical, taking hours to solve.
    • She came up with a diabolical plan to get back at her brother for hiding her phone.
Antonyms
What does "diabolical" mean? | whatsthatwordmean | whatsthatwordmean