The term 'Sly Hero' can be summed up by the crossword solution 'Rambo, ' a five-letter word. Rambo is the main character of the popular action movie series of the same name, which follows the story of John Rambo, a Vietnam War veteran who uses his combat skills to take on dangerous missions. He is known for his cunning and resourcefulness in battle, making him a perfect example of a sly hero.