When the Green Lantern series was first announced, Greg Berlanti described the project as “what promises to be our biggest DC show ever made.” He later dished on a few ore details, which Sarah Aubrey shared during the January 2020 TCA panel. The most interesting tidbit? The Green Lantern series will “span several decades” and go “into the Sinestro story.”
With Green Lantern focusing on multiple Lanterns in the Corps and stretching across a massive chunk of time, there will probably be a confusing timeline for fans to try and wrap their heads around. There are nine different Lantern Corps, but the Green Lantern Corps (the most well-known of the nine) are the protectors of our and every other world, with each member tasked with protecting a different sector of the universe.
A former Green Lantern Corps member, Sinestro was dismissed from the organization with an dishonorable discharge, and has since formed the Sinestro Corps, who do basically the exact opposite of the Green Lantern Corps. They seek to instill and rule by fear, using the yellow power ring as their source of strength. Sinestro is also the nemesis of Hal Jordan, becoming such after Hal was the one to bring about his fall from grace. That said, if Hal’s Green Lantern is part of the upcoming series, some tension between the pair would certainly be written into the plot. In that case, the Green Lanterns may be fighting villains from both the outside and within.