While the punch with infinite mass - that power comes at a price. When Flash's speed goes wrong, it goes very wrong. In the best-case scenario, that sometimes means a pair of broken legs, and in the worst, it means damaging the entire multiverse. However, easily the most disgusting consequence of Flash's power happened when he was forced to jump to top speed in order to save hundreds of people from a living god.
The Justice League Elite were an offshoot of the main team comprised of former villains looking for redemption. To keep the group in line, Batgirl, Green Arrow, and Flash ed up, taking on villainous new identities while infiltrating a cosmic drug cartel. Unfortunately, when rogue psychic Manchester Black was able to colonize the body of team leader Vera, he seized control of the cosmic entity Eve - a being able to change reality with a thought. Manchester Black immediately ordered Eve to unleash a devastating explosion aboard the cartel's spaceship base, at which point Flash jumped into action.
In Justice League Elite #9 - from Joe Kelly, Doug Mahnke, Tom Nguyen, David Baron, and Pat Brosseau - readers see the consequences. Despite Eve's near total command of reality, Flash is able to rescue over a hundred people from the cartel's base, but he has to push himself to his limits to do it. This amount of strain leaves Flash in a chaotic state, as his body becomes gelatinous 'velociplasm.' While Green Lantern is able to create a device to help Flash reconstitute himself, Wally West is trapped in a disgusting limbo where his body is attempting to reform itself, resulting in some truly dark body horror for the Fastest Man Alive.
The Speed Force allows Flash to bend the rules of physics to breaking point, but there are still some natural laws he must obey, and one is that his body apparently enters a gelatinous state to allow him to travel at impossible speed. Pushed too far too fast, Wally West is trapped in this state, and dependent on his Justice League allies to help him once again become flesh and bone. This velociplasm state is a hugely underexplored aspect of the Scarlet Speedster's abilities, and even suggests that along with his staggering range of powers, he may be able to shapeshift or otherwise change his form under the right circumstances.
Flash's personality means he has a tendency to act first and think later, but that's exactly what makes him such an effective hero. While being trapped as velociplasm was a disturbing experience for Wally West - and way darker than anything fans are likely to see in the DCEU - it showed the shocking lengths he will push himself to in order to save every person possible, and proved that as many Flash adventures as there have been, there's always a new aspect to his speed powers to keep fans intrigued.
