There Is No Justice League
Sinestro wields a power ring that grants him flight, the ability to survive in any environment, and the ability to create constructs of any shape and size. The ring must be regularly recharged with the aid of a power battery shaped like a lantern. For much of his villainous career, he wielded a yellow ring built for him by the Qwardians.
The first yellow ring is acquired by Thaal Sinestro following his banishment to the antimatter universe of Qward, and could only be recharged by fighting a Green Lantern. After his imprisonment in the power battery his ring was taken by Guy Gardner who used it until it was destroyed by Parallax. Upon his return to life, Sinestro was seen wearing a new yellow power ring. Before he could be defeated Sinestro retreated to the anti-matter universe where he spent the year creating his Sinestro Corps.
Yellow Power rings are now fueled by fear instead of willpower, but function the same as their green counterparts. Members of the Sinestro Corps are chosen for their ability to instill great fear in others. In order to become a member of the Sinestro Corps, one must free themselves from a small prison. With their yellow power ring completely drained of its energy, they must provide it with the spark it needs to accomplish this feat by facing their own greatest fear. Originally Yellow rings could be charged by Manhunter androids that have yellow power batteries built into themselves, which in turn are connected to the Central Yellow Power Battery on Qward. There are also portable batteries similar to those used by Green Lanterns
Sinestro was born on the planet Korugar in space sector 1417. His dedication to preserving order originally manifested in his previous career, an anthropologist specializing in reconstructions of ruins of long-dead civilizations. One day while he was on one such site, a Green Lantern named Prohl Gosgotha crash-landed into the site, injured and apparently dying. He quickly gave his ring to Sinestro, just in time for Sinestro, who barely even understood what the ring could do, to defend himself from the Lantern’s pursuer: a Weaponer of Qward; however, Sinestro had to destroy the ruins he had spent loving care restoring in order to crush the Qwardian. Afterward, Gosgotha turned out to still be alive and asked for his ring back to keep him alive long enough to get help. Sinestro, knowing this would mean not being a Green Lantern himself, instead allowed him to die and took over his post. The Guardians were unaware of his actions.
His desire for order did well by him in the Corps, and initially led him to be considered one of the greatest Green Lanterns. As the years passed, he became more and more fixated upon not simply protecting his sector, but on preserving order in the society of his home planet no matter the cost. Eventually, he concluded that the best way to accomplish this was to conquer Korugar and rule the planet as a dictator.
For using the power of the Green Lantern to instill fear rather than combat it, the Guardians banished Sinestro to the antimatter universe, a counterpart to the “real” universe made up of “negative matter”. Sinestro ended up on the Antimatter world of Qward, that universe’s counterpart of the Guardians’ homeworld Oa, which was ruled by a race of warriors and scientists known as the Weaponers of Qward, who bore a fierce hatred of the Guardians and all Green Lanterns. By exiling Sinestro to a world ruled by evil beings who specifically hated him as a Green Lantern, the Guardians hoped to humble him. However, their attempt at punishment would be a major miscalculation. Sinestro believed himself to have been wronged by his former masters and now hated them just as much as the Weaponers did. Through their mutual hatred of the Guardians, Sinestro and the Weaponers became allies, with the Weaponers offering to help Sinestro gain revenge on the Guardians and the Corps.
Creating a yellow power ring for Sinestro to use, the Weaponers sent him back to the “positive matter” universe to seek his revenge. Sinestro quickly became the Green Lantern Corps’ most powerful nemesis, partially due to a weakness in their power rings that prevented them from directly affecting the color yellow. Despite this, skilled Green Lanterns like Jordan, Sinestro’s most hated enemy, always found ways to defeat him.
He made a pact with the Anti-Monitor and embraced the doctrine of spreading fear. The Green Lantern Corps is once again reformed with the return of Hal Jordan so Sinestro decides to found the Sinestro Corps, offering yellow power rings and a role in the Corps to the most feared and savage warriors of the universe.