The Flash went in some unexpected directions with its villains in Season 5. The big bad was seemingly Cicada, who was later replaced by Cicada II, who was later eclipsed by Reverse-Flash as the villain with the real master plan. The show still found the time to introduce some promising side villains, with the speedster Godspeed as one of the most exciting. Surprisingly, he was a one-and-done in Season 5, but showrunner Todd Helbing revealed that the show isn't done with him, saying this:
There's small Easter eggs, there's big Easter eggs. When we were in Season 3, Savitar was talking about DeVoe being one of his biggest foes. We like to leave it up to the fans to try to figure out which its going to be. Who's maybe a big bad the next season, who's just a name drop. Godspeed sort of fell into the best of both worlds. We can have an episode with him, introduce him and then bring him back at some point in the future because he's a major comics villain so we would never want to do a guy like that in just one episode.
As Todd Helbing said in a chat with ComicBook.com, The Flash did give away The Thinker as the Season 4 supervillain during Savitar's stint as the big bad in Season 3. The Flash didn't reveal the identity of the Season 6 baddie like it did DeVoe, and Helbing's comments indicate that Godspeed will not be the big bad. But he will likely be back!
Even if Godspeed never becomes a villain on the scale of Reverse-Flash or Savitar or even Cicada, he is major enough on the pages of the comics and left with so much unfulfilled potential in Season 5 that it would be a shame if we never saw him again. Of course, Godspeed was Nora's enemy in her own timeline, so if he does come back, he'd presumably either have to travel to the past or the good guys would have to visit the future.
Notably, Todd Helbing did not name Red Death as a villain like Godspeed who could just drop in and out in the future, which does make sense. Red Death has the potential to be an incredibly iconic and terrifying Flash villain, although Helbing acknowledged that there are conversations that would happen with DC Comics before Red Death could appear. Perhaps the tease of a Red Death appearance will come to nothing. If so, at least we can likely count on more Godspeed!
All of this said, Todd Helbing is actually stepping down as The Flash showrunner ahead of Season 6, and he'll be replaced by executive producer Eric Wallace. It should be interesting to see if the show will feel different under the new showrunner. It doesn't mark the first time The Flash lost a head honcho.
The Season 5 finale was a game-changer in many ways thanks to some major deaths and departures, so there's a lot to consider during hiatus. All four shows in the Arrow-verse will return in the fall, although Arrow will end after a shortened eighth season, and something much battier will become a part of the universe.