Warning! This post contains spoilers for The Flash season 7 finale.
Bart and Nora. To defeat Godspeed, Barry called upon the only person who could help without permanently altering the future.
In The Flash’s season 7 finale, called “Heart of the Matter, Part 2,” Barry agreed to give Godspeed what he ultimately wanted: organic speed. Bestowed with the power of the Speed Force, The Flash and the villainous physicist battled each other. However, Barry and Iris had a backup plan — have the Speed Force tap into the Negative Speed Force to bring back Reverse-Flash in a bid to defeat Godspeed for good without putting Bart (aka, Impulse), Nora (aka, XS), and their future in danger. To no one’s surprise, Reverse-Flash turned on Barry immediately afterward. While the Scarlet Speedster was able to best Eobard Thawne in that moment, the villain vowed to become the fastest speedster alive again as the threat of his return loomed over the episode.
The season 7 finale wasn’t the first time Reverse-Flash reappeared after his death in The Flash’s season 1 finale. The speedster villain has popped up at several points throughout the series’ run, be it in the past, in an alternate reality, or as a time remnant. But the way Thawne was brought back this time around suggests season 8 of The Flash will be the end of the series. Reverse-Flash is the ultimate baddie from the show’s long history of villains; he’s also someone who shares the deepest personal connection with Barry, with Thawne’s murder of Nora Allen being what kicked off the series to begin with. To that end, it makes a world of sense that he would be the villain The Flash fights in its final season, bringing the events of the show full circle. Tom Cavanagh teased that The Flash and Thawne would settle things before the series officially came to an end.
It’s been confirmed Grant Gustin’s contract ends with The Flash season 8, so if there was ever a time to stage a final battle between the two speedster enemies, next season would be the opportune time to do so. Of course, the actor's contract could be renewed, but with Thawne showing up, a looming pregnancy for Iris, and the original cast dwindling, it's unlikely The Flash will carry on for much longer. Plus, if Reverse-Flash wasn’t coming back next season, there wouldn’t have been a purpose to his appearance in season 7 finale. It’s possible Reverse-Flash will spend time off-screen ensuring he becomes the fastest man alive as Barry deals with another villain first. When he’s satisfied with his powers, that’s when he might return to have a final showdown with The Flash, which could happen nearer to the end of the eighth season.
Reverse-Flash’s return has been hinted at for a while now, but his appearances have always been in brief, fleeting bursts. However, the season 7 finale of The Flash fully committed to the promise of the speedster being a more permanent and antagonistic fixture in the future. Considering his history with Barry and The Flash being on its last leg as far as longevity, bringing back Thawne and having Barry defeat him once and for all feels like a suitable end to the Scarlet Speedster’s story.