THE FLASH
>Season 6 will be split into two story arcs, Pre-Crisis and Post-Crisis, each with its own main villain.
>Sendhil Ramamurthy has joined the cast as Dr. Ramsey Rosso / Bloodwork, the main villain of the Pre-Crisis arc. He’s an old friend of Caitlin who joins S.T.A.R. Labs and is secretly obsessed with “curing” death itself, leading to his transformation into Bloodwork.
>Barry is struggling with Nora’s death and its impact on the timeline, such as Godspeed still being on the loose.
>Iris is now managing the Central City Citizen and its staff of reports, which might include Sue Dearborn.
>Cisco is once again the “guy in the chair” after losing his powers.
>Ralph’s family will be introduced and his past will be explored.
>Wally will return and help Barry fight one of the Flash’ greatest villains.
>Season 6’s Harrison Wells will be the Pariah.
>Eobard Thawne will return for CRISIS.
ARROW
>Oliver’s mission is recruiting an army of superheroes from across the Multiverse to help stop the Crisis.
>Charlie Barnett has joined the cast as John Diggle Jr., who is the leader of the Deathstroke Gang in the 2049 storyline.
>Stephen Amell will play multiple versions of Oliver Queen in CRISIS.
BATWOMAN
>Season 1 will be relatively standalone, crossover aside.
>Alice and the Wonderland Gang are the main villains of season 1, but several notable Batman villains will be featured, although many of them will be different as a result of Batman's mysterious disappearance.
>Tommy Elliot / Hush will be a pivotal villain in season 1, but he will be different from the comics version, particularly his origin.
>They are not allowed to use Batman at the moment, but that might change if the show becomes popular, like it happened with Superman in SUPERGIRL. Batman's presence is still felt in the show in the form of his crimefighting diaries, which Kate finds and frequently consults.
>Batwoman and Supergirl will develop a close bond during CRISIS.