If you missed any of our Blackest Night primer, make sure to check out the index post for basic information, links to all the other posts and the schedule for upcoming posts. When you're ready, hit the jump for everything you need to know about the Sinestro Corps.
Emotional Spectrum: Fear
First Appearance: Green Lantern #10 (as a Corps)
Homeplanet: Qward (Sector -1 of the Anti-Matter Universe)
Leader: Sinestro; Renegade faction led by Mongul
Key Stories: Sinestro Corps War, Rage of the Red Lanterns, Emerald Eclipse
Beware your fears made into light.
Let those who try to stop what's right,
Burn like his power -- Sinestro's might!"
It would be years before Geoff Johns explained that the yellow ring actually harnessed fear from emotional spectrum. The culmination of all this came with Sinestro's realization that to combat the Green Lantern Corps, he would need his own corps to be on even footing and, thus, the Sinestro Corps was born. Recruitment began shortly after Johns rebooted the Green Lantern franchise with Green Lantern: Rebirth and saw Sinestro's new corps expand rapidly, seemingly rivalling the Green Lantern Corps in numbers overnight and resulting in their debut at the onset of the Sinestro Corps War.
Initiation: Unlike Green Lantern rings, which seek out people that can overcome great fear, the Sinestro Corps rings seek out those that can instill great fear. Furthermore, the Sinestro Corps rings literally gangpress new recruits into the corps and immediately teleport them back to Qward in the Anti-Matter Universe so they can be "subjected to psychological and physical reconditioning".
Finally, each new recruit, once trained under Arkillo, the Sinestro's drill sergent, must undergo a final trial whereby they are placed in an isolation chamber in complete darkness with their new ring, which is drained of all power, and forced to either harness fear to light their ring or die trying.
Powers:Sinestro Corps rings harness fear from the emotional spectrum to create yellow light constructs. With the exception of harnessing fear and being yellow, Sinestro Corps rings appear to be all but identical to Green Lantern rings in strength and function.
Weaknesses: Sinestro Corps rings are weak against Blue Lanterns, who can drain their power. Combined with the fact Green Lanterns are weak against red and orange light, the two emotions farthest from them on the spectrum, it is possible that yellow, also in the middle with green, is weak against violet (Star Sapphires) and/or indigo (Indigo Tribe). Kryb was easily taken down by the Star Sapphire, Miri, where several Green Lanterns failed, and they are already shown to be weak against blue, so it is very likely these weaknesses may be shown during Blackest Night.
As touched upon in the Green Lantern Corps section of this primer, Sinestro is a former Green Lantern and was, at one time, viewed as the greatest Green Lantern ever. When it was revealed that he actually used his Green Lantern ring to instill fear in the populace of his sector as a would-be dictator, the Guardians stripped him of his ring and banished him to the Anti-Matter Universe planet of Qward.
There, Sinestro met the Weaponers of Qward, who fashioned a yellow power ring for him. Sinestro would use this ring to fight back against the Guardians and Green Lantern Corps and, eventually, it was the inspiration for forming an entire corps of yellow ring users.
Sinestro has only considered two people to be his friends over the years, Abin Sur and his eventual replacement, Hal Jordan. Despite everything that has happened, it appears that Sinestro still respects Hal Jordan and considers him a friend.
It was recently revealed that Sinestro has a daughter, the Green Lantern, Soranik Natu, whom he has kept hidden and watched over for all these years. When Atrocitus revealed he knew of his daughter, Sinestro was forced to confront her and reveal his identity as her father. Natu outright rejected him, but has come to accept the knowledge that he is her father.
Long thought dead at the conclusion to Crisis on Infinite Earths, the Anti-Monitor was reborn during the creation of the new Multiverse in 52 and became the Guardian of Fear of the Sinestro Corps. Seeking the destruction of the positive matter universe, the Anti-Monitor led the Sinestro Corps to Earth, where he attempted to wipe out the new cornerstone of the Multiverse, which would have cascaded and destroyed every other Earth, leaving only the Anti-Matter Universe.
Through the combined efforts of the Green Lantern Corps, Guardians of the Universe and even Superboy-Prime at the conclusion to the Sinestro Corps War, the Anti-Monitor was defeated and Prime threw his dying body into space, where it was then captured on the dead planet, Ryut, in Sector 666, the same place as the Manhunter Massacre of Sector 666 took place, and imprisoned inside a giant black lantern, where his powers now serve as the Central Power Battery of the Black Lantern Corps.
Parallax is the emodiment of fear. Long imprisoned inside the Green Lantern Central Power Battery on Oa, Parallax was revealed to be the source of the yellow impurity in the Green Lantern rings, which prevented them from being used on anything yellow.
When Sinestro was imprisoned in the Central Power Battery for his crimes, he learned of Parallax and developed a plan that would see it corrupt and possess Hal Jordan, who would go on to destroy the previous encarnation of the Green Lantern Corps.
During the Sinestro Corps War, Sinestro used Parallax to possess Kyle Rayner, who then became a herald of the Sinestro Corps and fought many of his fellow Green Lanterns before being defeated. Parallax was then extracted from Kyle and separated into four pieces, each piece residing inside one of the four Earth-based Green Lantern's personal power batteries, where Parallax has remained since.
Mongul (Sector 2811)
The current Mongul, who is attempting to take over the Sinestro Corps, is the son of the first Mongul, who destroyed Hal Jordan's hometown, Coast City, which eventually led to Jordan's breakdown and possession by Parallax. Despite having some run-ins with Hal Jordan early in Johns' relaunch, this Mongul didn't clearly establish himself as a Green Lantern villain until recently when he came upon a Sinestro Corps ring. He quickly began 'collecting' (aka killing Sinestro Corpsmen for their rings) rings and has in his possession at least six, if not more, rings for his own personal use.
Using these rings, he went about establishing his powerbase within the leaderless Sinestro Corps faction post-Sinestro's capture at the end of the Sinestro Corps War. Recently, he attempted to take over Daxamite. After enslaving the local Daxamite population and defeating Arkillo for control of this faction of the Sinestro Corps, Mongul was forced to fight Ion, who had come to aid his former people and home. Ion sacrificed himself in the Daxam red sun, where he used the Ion power to convert it to yellow, which gave his Kryptonian-like people Superman level powers. This allowed them to easily fight back against their oppressors and forced Mongul to issue a retreat command. Mongul was last seen stating he had another planet in mind for a base of operations.
Also, Sinestro is aware of Mongul's actions and has plans to deal with him at some point in the future, most likely during Blackest Night.
Hal Jordan (Sector 2814)
While not technically an actual member of the Sinestro Corps, much like he did with every other corps he's run into, Jordan did, in fact, use the Sinestro Corps rings. There was also his lengthy time as Parallax, which, while predates the Sinestro Corps, consisted of him championing their cause and spreading fear.
Amon Sur (Sector 2814)
The son of Green Lantern, Abin Sur, Amon was murdered during the act of surrender to the Green Lanterns by Green Lantern, Laira. This act, combined with the new laws initiated on Oa, caused the creation of the Alpha Lanterns and Laira's expulsion from the Green Lantern Corps and eventual induction into the Red Lanterns. As Amon is the son of the famous Green Lantern, Abin Sur, and recently died, he is all but a lock for a potential Black Lantern.
Arkillo (Sector 674)
Sinestro Corps drill sergent, similar to Kilowog of the Green Lantern Corps. When Mongul attempted to take control of a faction of the Sinestro Corps, Arkillo was the only one to stand up to him. During a one on one battle for control of the Sinestro Corps, Arkillo suffered a humiliating defeat in which Mongul ripped out his tongue. Left to live with his shame, Arkillo currently wears his tongue as a necklace and, while he still serves under Mongul, continues to plot his revenge.
Cyborg-Superman (Sector 3601, formerly 2814)
The former Superman villain was responsible for the destruction of Hal Jordan's hometown, Coast City, and its millions of inhabitants. This act drove Hal Jordan insane and allowed him to be possessed by Parallax.
At some point before the Sinestro Corps War, Cyborg-Superman became the leader of the Manhunters and was eventually captured by the Green Lanterns. Freed of his imprisonment by Sinestro during the Sinestro Corps War, Cyborg-Superman pledged loyalty to the Anti-Monitor in exchange for his own death. He had become tired of life and his immortal existence and where every other attempt at dying failed, he believed the Anti-Monitor would succeed.
While he appeared to die during the Sinestro Corps War, the epilogue showed the Manhunters finding several parts of him and reviving him. He has not been seen since, but his connection to the Sinestro Corps and the Manhunters, whom have a storied past with the Guardians, Atrocitus and the Massacre of Sector 666, along with Cyborg-Superman's desire for death, it is believed he may return at some point during the Blackest Night.
Fatality (Sector 1313)
Former enemy of John Stewert and Kyle Rayner, Fatality was briefly a Sinestro Corps member before being captured by the Star Sapphires. The Star Sapphires placed her in a conversion chamber, which she recently emerged from, and she is now counted as one of their members. Whether the conversion will prove temporary or if her former Sinestro Corpsmen will seek revenge on a perceived traitor is left to be seen.
Kryb (Sector 3599)
Deadly and powerful Sinestro Corps member that instilled great fear across the universe through the theft of babies, the babies of Green Lantern parents in particular, and murder of their parents, Kryb was recently subdued and captured by the combined efforts of a squad of Green Lanterns and the Star Sapphire, Miri. Miri took Kryb back to Zamaron where Kryb was last seen in a conversion chamber, where they were attempting to covnert her into a Star Sapphire, similar to what they did to Fatality.
Lyssa Drak (Sector 3500)
Lyssa Drak served as the keeper of the Book of Parallax, which is similar to the Book of Oa for the Green Lanterns, but was captured at the conclusion of the Sinestro Corps War. Recently freed during the riots in the Sciencells on Oa in Emerald Eclipse, she sought out the Book of Parallax only to stumble upon Scar's Book of the Black, which was hidden deep below Oa. While looking through the book, Scar grabbed hold of Lyssa and pushed her into the book, where she was shown trapped inside the very pages she sought to steal. Her fate remains unknown since then.
Superboy-Prime (Sector 2814 of Earth-Prime)
Prime was freed from his imprisonment on Oa by the Sinestro Corps during the Sinestro Corps War and went on to become their herald. However, he did so only as a means of getting close to the Anti-Monitor, whom he blamed for all his hardships, and eventually turned on his fellow corpsmen and, in the end, helped defeat the Anti-Monitor. He then took the dying corpse of the Anti-Monitor and threw it into space, where it was found and turned into the Black Lantern's Central Power Battery. While Prime is not expected to play any part in the Blackest Night or with the Sinestro Corps any time soon, he was an instrumental part at one point and deserves mention.