The Reverse Flash costume matches that of the comic book Earth-X Flash, but it wasn’t known until now whether or not the Arrowverse Earth-X would be played by Grant Gustin or someone else.
Behind-the-scenes photos from the filming of the Earth-X crossover event confirm that Reverse Flash is back. The Flash fans are loving the return of the fastest man alive, and they’re looking forward to the big event of the Arrowverse this season: a massive Earth-X crossover event that will bring together Arrow, The Flash, Legends of Tomorrow, and Supergirl in a four hour special over two nights.
The images also show Grant Gustin in his red Flash costume walking next to Cavanagh (wearing only part of his costume).
The suit matches that of the Earth-X Flash on the poster, with the yellow chest turning into a black suit below the waist.