In season five, Oliver trains up young heroes Wild Dog (Rick Gonzalez), Mister Terrific (Echo Kellum), Artemis (Madison Mc Laughlin) and Ragman (Joe Dinicol) to join him in his war on crime following Laurel's death and Thea and Diggle's resignations, while he tries his best to balance his vigilantism with his new role as mayor.Oliver also faces the threat of a dark and shadowy enemy named Prometheus, who has a deep-rooted vendetta against him.That May, the CW officially confirmed DC's Legends of Tomorrow for a January 2016 premiere.In October, additional Arrow showrunner Wendy Mericle revealed that the producers had begun having someone track all the characters and plots used by each series, in order to make sure everything lines up, though The Flash executive producer Aaron Helbing noted in April 2016 that "sometimes the schedules don’t line up exactly..that stuff is out of our control", such as when the Flash is shown using his abilities on Arrow that month, while not having them the same week on The Flash.The franchise has also crossed over with DC Comics television shows which air on other networks; Arrow crossed over with the short-lived NBC live-action series Constantine in the former's fourth season, while there was a crossover with the CBS series Supergirl, followed with multiple crossovers after Supergirl moved to The CW.
The shared universe, much like the DC Universe in comic books or the cinematic DC Extended Universe, was established by crossing over common plot elements, settings, cast, and characters.
His obsession with his tragic past causes him to become an outcast among his peers; he investigates cold cases, paranormal occurrences, and cutting-edge scientific advancements that may shed light on his mother's murder. Labs malfunctions during its public unveiling, bathing the city center with a previously unknown form of radiation and creating a severe thunderstorm.
No one believes his description of the crime—that a ball of lightning with the face of a man invaded their home that night—and Allen is fiercely driven to vindicate himself and to clear his father's name. Allen is struck by lightning from the storm and doused with chemicals in his lab.
The animated web series Constantine will join the franchise in 2018.
Two promotional tie-in live-action web series, Blood Rush and Chronicles of Cisco, were released in 20 respectively.