WARNING: This article includes SPOILERS from The Flash season 8 finale
The Flash showrunner Eric Wallace explains how the massive season 8 finale post-credits scene sets up the Arrowverse show's season 9. While The CW slashed multiple Arrowverse shows this year, including Legends of Tomorrow and Batwoman, The Flash is still going strong. It became the Arrowverse's longest-running following episode 171, which served as part 2 of the season 8 finale. In the final two episodes of The Flash season 8, the DC TV show saw Barry Allen take on a leveled-up Reverse-Flash, with the assistance of the Negative Forces.
While The Flash season 8 finale was initially set to work as a series finale, this was before The CW renewed the show for a season 9. Nevertheless, season 8 wrapped up most of the show's big storylines from this year, including Iris West-Allen's time-sickness. However, like most of the previous seasons, the finale didn't leave fans without a taste of what is to come in season 9. Towards the final minutes of The Flash season 8 finale, the show included a post-credits scene that will set up season 9.
Even though The Flash season 9 won't be arriving until 2023, the post-credits scene is a big mystery that is meant to be recognizable for DC fans. Following the season 8 finale, TVLine spoke with showrunner Wallace about the big finish, but also the ambiguous post-credits scene. When asked about the scene with the secret blue crystal, Wallace teases it's something that "hardcore comic book fans" will be able to recognize, in terms of what The Flash season 9 is doing. Here's what Wallace says about the setup for The Flash season 9:
The hardcore comic book fans know what’s coming; those who don’t, I’m not spoiling it here, so it’s going to be a big surprise for them. But yes, we’re pulling directly from the comic books here, and boy is it going to be fun.
In the final moments of The Flash season 8 finale, as Barry and Iris were having a romantic moment, the latter brought up that the Negative Speed Force will need a new avatar at some point. As they had their talk, the scene cuts to June 29, 2049, exploring what seemed to be a lab of some kind. The camera then pans over to a blue crystal, which is what Wallace was directly referencing as the big setup for The Flash season 9.
If Wallace's season 9 comment is meant to be an allusion to something directly from The Flash comics, there is one major possibility who may be the owner of that blue crystal. A villain that many have wanted to see for years is Malcolm Thawne, a.k.a. Cobalt Blue, who was Barry's long-lost twin brother in older Flash comics. A popular The Flash fan theory for several years has been that Rick Cosnett, who played Eddie Thawne, would somehow become the Arrowverse's Cobalt Blue if the show ever chooses to explore that. If that's the direction set for The Flash season 9, it would certainly be interesting to see the Arrowverse adapt that character, who hasn't been in the comics for several years.
Source: TVLine