The CW promised more surprises are on the way for The Flash Season 9, and a new report may have revealed one surprising Arrowverse guest star.
Ahead of The Flash's final season, new details about certain Arrowverse guest stars have slowly emerged online.
Stephen Amell's Green Arrow is set to make an unexpected comeback alongside Javicia Leslie's Batwoman, Nicole Maines' Nia Nal, and David Ramsey's John Diggle.
Despite those confirmed crossovers, The Flash Season 9 appears to be not finished yet with stunning surprises.
The Flash Season 9 Brings Back Major Season 1 Character
Canadagraphs shared that Rick Cosnett filmed scenes for The Flash Season 9, though the outlet isn't sure which character he was playing.
Cosnett portrayed Eddie Thawne in The Flash Season 1, but he later sacrificed himself to save Team Flash against the Reverse Flash. Cosnett later reprised his role in The Flash Season 8 Episode 13 via a flashback and form taken by Deathstorm.
Canadagraphs also revealed that The Flash Season 9 Episode 10's title is "A New World: Part One," indicating that it could be an alternate reality or a different timeline:
"There are two details I picked up while I was there on the first day by dumb luck. One is, a guest star that ALSO filmed on the Monday set, but unfortunately not while I was there, that is Rick Cosnett was working that day. I DO NOT KNOW the character he was playing, so dont get carried away with speculations. The other, is the episode title, which I found curious. 'A New World: Part One'."
Why Did the Flash Resurrect Eddie Thawne? (Theory)
It appears that The Flash Season 9 is going all-out in bringing back notable Arrowverse characters for one final appearance.
Rick Cosnett's return as Eddie Thawne has been the subject of fan theories ever since his death in Season 1, with some speculating that his comeback would mark his transformation into the evil DC supervillain known as Cobalt Blue.
Based on the episode's 'New World' title, The Flash Season 9 may be set to tackle a different timeline, considering that this is also the same episode where Barry Allen's parents are still alive alongside Joe West, who is still a cop and not retired.
That said, seeing Eddie in the episode wouldn't be surprising because he is Joe's former partner in the Central City Police Department. However, there could be an added twist.
During the tail-end of The Flash Season 8, Cobalt Blue's presence was teased, meaning that this could be addressed in this upcoming episode.
Fueled by jealousy and hatred due to Barry and Iris West ending up together in the present, Eddie (as Cobalt Blue) may have been responsible for this new world.
From time travel shenanigans to an alternate Multiverse variant of Eddie (fans already saw an evil Batwoman from a different Earth), there are many ways for the Thawne ancestor to return.
By looking at the bigger picture, Eddie's return as Cobalt Blue may have something to do with Reverse Flash's resurrection. The Flash Season 8 proved that Eobard Thawne is a master manipulator and could be using Eddie as a means for his return.
Reversing Eddie's death could also be the first step in bringing back Reverse Flash.
Once the evil speedster returns, The Flash Season 9 could come full circle as it might eventually lead to Season 1's climactic moment: Reverse Flash killing Barry's mother.
The Flash Season 9 is set to premiere on The CW on Wednesday, February 8 at 8 p.m. ET/PT.