Utterly fearless and a master tactician, Sinestro was chosen by the Guardians of the Universe to patrol Space Sector 1417 as its Power Ring wielding Green Lantern. Instead, Sinestro turned his home world of Korugar into a veritable police state which he ruled over with an emerald fist, unbeknownst to the Guardians. Soon Sinestro was charged with the task of training fledgling GL Hal Jordan. The Korugarians used Sinestro’s absence as opportunity to free themselves from his tyranny, thus exposing Sinestro’s abuse of his power. The Guardians of the Universe stripped Sinestro of his mantle and Power Ring, subsequently banishing him to the anti- matter universe of Qward. There, Sinestro allied himself with the Qwardians—sworn enemies of the Guardians—and eventually returned to the positive-matter universe armed with a yellow Power Ring. Since the Green Lanterns’ Power Rings contained a necessary impurity that rendered the weapon ineffective against anything coloured yellow, Sinestro became the Green Lanterns’ greatest foe. Ever since, Sinestro has battled his former pupil Hal Jordan and the entirety of the Green Lantern Corps in his quest for greater power. He is ruthless and utterly without remorse, making Sinestro a villain feared throughout intergalactic space.