Of all the moves Flash has in his repertoire, one is so dangerous he can't use it except for the most dire circumstances. Dark Nights: Death Metal Speed Metal #1 reveals why Wally West can't frequently use the greatest application of his abilities.
As some of the fastest people in the DC Universe, the Flash Family has a number of tricks up their sleeves to bring out the best of their amazing powers. Thanks to their connection to the Speed Force and the science behind their many 'Flash facts', the speedsters have been able to pull off amazing stunts like the infinite mass punch or even a limited degree of running on air. While Flash and his allies have a mastery over their power, that doesn't mean they don't have to be careful when using it. As many speedsters have discovered, the Speed Force can be quite unforgiving, even for Flashes.
Case in point, Wally West revealed that there's one power that can give him and his allies a serious boost, but at a serious cost. In Dark Nights: Death Metal Speed Metal #1 and Joshua Williamson and Eddy Barrows, Wally is being hunted by the Darkest Knight, aka the Batman Who Laughs, as he wants the godlike Manhattan power that the Flash has within him. Wally, along with Barry Allen, Wallace West, and Jay Garrick, are running for their lives as they are pursued by a group of Black Flashes the Darkest Night has unleashed. With the Speed Force burning out, Wally is forced to pull out a trump card. He speaks the Speed Force formula pioneered by Johnny Quick, which causes time to completely stand still. Kid Flash notices his speed draining with Barry pointing out this move accelerates Speed Force burnout.
Flash's Ultimate Move Is Effective, But Dangerous
The formula that helped give Johnny Quick his speed powers is a good way for average humans to tap into the Speed Force if they’re not already connected. Having already been blessed by connections to the mysterious phenomenon, people like Wally or Barry would have no need to utter the phrase. But it seems that those who are channeling the Speed Force can enhance their own abilities by speaking the formula. Unfortunately, the added power comes with a drawback that makes it not worth it.
Being able to freeze time when necessary is an amazing ability (and a lifesaver in the Flash Family’s case). But it puts a heavy strain on the Speed Force, which not only affects the speaker of the formula, but all other speedsters. It essentially creates a small amount of breathing room in exchange for a ticking clock that counts down to the Flash’s powers failing. It’s something that helped Wally save his allies from an army of evil speedsters, but it could have just as easily led to their deaths. Freezing time may be a highly effective power, but it’s something the Flash knows is only for doomsday scenarios.