'Arrow' season 5 air date, spoilers news: Oliver created Prometheus? 'Big things' ahead for Felicity

Oliver Queen/Green Arrow (Stephen Amell) will be facing an all-new villain known as Prometheus in the upcoming "Arrow" season 5.
While not much has been revealed about Oliver's new adversary, "Arrow" executive producer Marc Guggenheim recently shared a major detail about the villain's past and his connection with Oliver. In an interview with Entertainment Weekly, Guggenheim said, "I can really only say that Oliver bears a measure of responsibility for the creation of Prometheus."
The "Arrow" boss shared with EW that the theme for the new season is "legacy," and that in it, Oliver, who will be juggling his responsibilities as masked vigilante and mayor, will be looking back on his journey.
"The idea [is] Oliver honoring Black Canary's [Katie Cassidy] legacy after Laurel's death last year," Guggenheim explained. According to the "Arrow" showrunner, season 5 will feature numerous flashbacks to season 1 as it plays out Oliver's desire to grow and evolve. Alongside the hero's wish to move forward, the concept of legacy will be pulling him back to the past.
As Oliver deals with his past and his legacy, his former fiancee Felicity Smoak (Emily Bett Rickards) will be kept occupied by the Havenrock catastrophe and by "big things" ahead.
In a separate interview with EW, Guggenheim revealed the first five episodes of "Arrow" season 5 will find Felicity dealing with the decision she made in the season 4 finale. Her choice ultimately led to the deaths of tens of thousands of innocents. After this, however, Felicity will begin to play a more active role in things.
"We're positioning her to do something in the second half of the year that is really, really key, and that isn't about her relationship with Oliver or even necessarily her father or her mother," Guggenheim told EW. "It's really new territory for her, and we've very excited about it. Some big things are going to happen with Felicity," he added.
"Arrow" season 5 premieres Wednesday, Oct. 5, at 8 p.m. EDT on The CW.