The Flash's super-speed is fully showcased in Zack Snyder's Justice League, and one scene hints at how it was planned to increase in the intended Justice League sequels. Barry Allen (Ezra Miller) is well-known to DC fans by the monikers of The Scarlet Speedster and The Fastest Man Alive. With the release of the Justice League Snyder Cut in early 2021, the world got to see Barry completely live up to both nicknames and his proper superhero title.
In the Snyder Cut, Barry's super-speed is depicted primarily through two means. Either the world around Barry slows down as he zooms by in a scaled-back version of his speed, or Barry's speed is shown to its fullest in a straightforward manner. The latter accounts for a scene in which Barry saves civilians from falling debris as he and Cyborg (Ray Fisher) get them to safety from the lair of Steppenwolf (Ciarán Hinds). This also quietly hints at how fast Barry was planned to become by Snyder.
RELATED: Justice League: Flash's Final Sprint Was More Important Than You Realize
In the outline for Snyder's unmade Justice League sequels, Barry's role in the final battle with Darkseid (Ray Porter) and Apokolips was to see him reaching the pinnacle of his super-speed. As described on the whiteboard blueprint, "The Flash is able to move so quickly, he masters his powers — existing in two places at once. Unstoppable, he takes out an entire army by himself." Barry's aforementioned civilian rescue in the Snyder Cut shows he's already well on his way to that speed level. However, Snyder's vision proves that The Flash still had a long way to go to reach his full potential.
In Barry's rescue of the kidnapped civilians, he zips from one spot to another with a speed that's one step below outright
Read more on screenrant.com