Sinestro

Sinestro''' is a supervillian that is the leader of the Sinestro Corps. He is most well known as an enemy of the Green Lantern Corps. He used to be in the Green Lantern Corps, but then instead turned into a yellow lantern.'''

Variants
Here is a list of known variants:
 * Sinestro (Sinestro Corps)
 * Sinestro (Green Lantern)

History
Originally known as the greatest member of the Green Lantern Corps ever to wield a ring, he trained many students including Hal Jordan. The Guardians of the Universe exiled him to the Antimatter Universe after learning he had used his power to set up a brutal dictatorship. Having fought the Green Lanterns for many years with a yellow ring, eventually he established his own Sinestro Corps to spread fear throughout the universe.