If you haven't gotten over to the CW Seed yet to watch the first six episodes of Freedom Fighters: The Ray, they've released a sneak peek at a scene that they call The Ray vs. Flash. Except that's not the Flash — it's Blitzkrieg, voiced by actor Scott Whyte. And if you've watched the Crisis on Earth-X crossover, then you realize that's not the evil Flash from there, either.
Without giving too much away, Freedom Fighters: The Ray is a prequel to the crossover. Hence we get to see Overgirl (Melissa Benoist). According to executive producer Marc Guggenheim, this animated series was done prior to the crossover being conceived of. Russell Tovey was cast after and his voice replaced whoever did the first recording. And what we see is Blitzkreig and Black Arrow instead of the Dark Arrow and Reverse-Flash from the crossover. Guggenheim acknowledges some continuity errors that he hopes to address in a comic if allowed.
The focus of this series is the origin story of The Ray of Earth-1, the one we meet in the crossover. But the series starts with the Freedom Fighters and the Ray of Earth-X… gotta love the way multiverse stories can get all confusing in seconds.