"Decebalus, the king of the Dacians, was terribly clever in his understanding of matters of war, and terribly clever in action and successful in making expeditions, well-timed in retreating, a master of ambush, a worker of war; and he used victory well and well he knew how to deal with defeat; because of which he was a battle-worthy antagonist for the Romans for a long time."[1]
"Terribly clever" [deinos] is also said of ability with words.[2]