Thaal Sinestro is a fictional character, an alien supervillain / anti-hero in the DC Comics Universe. Created by John Broome and Gil Kane, Sinestro is the former mentor of Hal Jordan and the arch-nemesis of the entire Green Lantern Corps. Sinestro first appears in Green Lantern (vol. 2) #7 (July–August 1961). In 2009, Sinestro was ranked IGN's 15th Greatest Comic Book Villain of All Time. Mark Strong played the role of Sinestro in the 2011 superhero film Green Lantern. While he was under the possession of the White Entity he was one of the most powerful characters in all of the DC universe.