DC Comics revolutionized the speedster type of hero and villain. A speedster is basically what it sounds like — a person with a superpower that allows them to move at high speeds. Sometimes, this means they can fly really fast, but it mostly refers to those who can run very fast. DC created the granddaddy of all speedsters in the Golden Age: the Flash. During an experiment with hard water, college student Jay Garrick gained the power to run at superspeed. Garrick would start a legacy that would run through the ages.
Barry Allen was the next Flash and became an icon. Every good hero needs a great villain, and for Barry Allen's Flash, the best villain was the Reverse-Flash. Eobard Thawne was a time traveler from the future who hated Barry. Using superspeed powers, Thawne haunted Barry's life. Both eventually died, with Barry replaced by his sidekick Wally West, but both would return to a DC Universe where their powers were much more well-defined. Reverse-Flash is the most dangerous Flash villain, which begs the question — who's more powerful? There are reasons that either could be considered the most powerful, as they both have amazing feats.
Reverse-Flash Gained Frightening New Powers Upon His Resurrection
The introduction of the Speed Force happened while Thawne and Allen were dead, and both of their powers had to be changed in order to work with the Speed Force. The less said about Barry Allen as the source of the Speed Force, the better, but Reverse-Flash got something very interesting in return. Reverse-Flash's powers, which had always been the exact same superspeed abilities that Barry Allen had, except more powerful and destructive, suddenly changed. For one thing, his body was often wreathed in red and black lightning, which could destroy another speedster with a touch. This allowed Reverse-Flash to kill quite a few speedsters upon his return, but it would become a power that Reverse-Flash would use less and less as things went on.
However, the greatest power that the Negative Speed Force gave Reverse-Flash involves time travel. Speedsters are known for being able to travel across time and space, but most time travelers can't actually change history in any way that sticks. Not so for the Reverse Flash. The Reverse Flash learned soon after he was resurrected that time was putty in his hands. It wasn't like changing history for him — whatever he did to time just became a part of the timeline. He started by slaughtering all the people in his old life that he hated. Reverse-Flash started to do the same to Barry Allen's past, and that culminated in killing Barry's mom and framing his father. This change led to Barry trying to use his powers to stop his mother's death and caused Flashpoint to happen.
Speedsters are superlatively powerful, with the Flashes being particularly potent. Barry was always the most skilled of the Flashes, and Reverse-Flash was easily his equal. There's no way to say who was faster except to say that both of them can move at light speed and beyond, vibrate through matter, and perform basic speedster tricks. Reverse-Flash's newer powers are the ones that show just how powerful he can be, especially his time-traveling powers. The Negative Speed Force has made Reverse-Flash into a temporal anomaly. He can change time, but time can't change him. In fact, it seems like even death itself can't phase the Reverse-Flash; he died at the end of Flashpoint but returned with his full memory of the other universe and was killed again by Doctor Manhattan later. He's shown up again each time.
The Black Flash chases the Flashes, a reminder of their on-rushing death. Reverse-Flash is somehow worse than the Black Flash, though. The Black Flash has no malice — it's just fulfilling its place in the universe. Reverse-Flash hates Barry Allen so much he'll destroy anything to hurt him. The Negative Speed Force makes Reverse-Flash more dangerous than ever, and his new status as a temporal ghost has made him the most feared of the Flash's enemies. This power would seemingly give him an advantage over any Flash, but that's not exactly the case.
Which Flash Is The Most Powerful?
So, before comparing the Flash's power level to Reverse Flash, it has to be decided which Flash to use. Jay Garrick, the first Flash, has had very little to do with Reverse-Flash and is the weakest but most experienced of the Flashes. Bart Allen, John Fox, and Avery Ho are all much lesser-known Flashes. Each of them is powerful, but no one would pick them to compare to Reverse-Flash. That leaves the two most popular Flashes — Barry Allen and Wally West. The Flash has kept Central City safe in one form or another for years, and Allen and West have been the ones who made the most difference. Each one has their own reasons why they should be chosen.
Barry Allen was the Flash that made the mantle popular again in the Silver Age, but he's also the one that almost destroyed the mantle. Barry Allen's death in Crisis On Infinite Earths wasn't just meant to make him DC's greatest saint; it was because his popularity had cratered, and DC was killing him both to give Wally a chance as Flash, to make sure the Flash didn't die out in obscurity and to represent the end of the Silver/Bronze Age, which Crisis On Infinite Earths was ending. Barry took up the mantle of the Flash again upon his return to life. He got the requisite speed boost that the revised Speed Force powers gave him access to. Beyond that, though, he's nowhere near the most powerful Flash. He can travel through time and the Multiverse, but he needs the Cosmic Treadmill to do so. He invented most of the Flash's best moves, but it's been a long time since he's actually manifested another new speed power. Barry is undoubtedly powerful, but he might not be the best to compare to Reverse-Flash.
Wally West is the current Flash. The first Kid Flash, Wally learned about using his speed from his uncle Barry, but that was only the beginning. Wally basically grew up as a hero. He helped found the Teen Titans and hung out with the greatest heroes in the world. He was a sponge who learned his lessons well. When he became the Flash, his powers weren't at their best, but all of that would change, ironically enough, against Reverse-Flash. Reverse-Flash came back in time in the classic story The Return Of Barry Allen, posing as the dead Flash and easily mopping the floor with the weakened Wally. However, Max Mercury, Johnny Quick, and Jay Garrick helped Wally learn about the Speed Force, and that changed everything for Wally.
Wally West mastered the Speed Force. Wally West wasn't a perfect hero like his uncle Barry, but he learned fast and was able to improvise. He learned his lessons well from Barry Allen, mastering the use of the Cosmic Treadmill, learning to expertly phase through matter, and even mastering the infinite mass punch. He's proven to be the fastest human being ever and has even outrun the Black Flash, which was heretofore thought impossible. He also became the most powerful channeler of the Speed Force and had one power that no other Flash had until he started teaching them — the ability to drain an object of the Speed Force and absorb its energy. He was able to do this to slow down foes and once used it to transform Inertia, the killer of Bart Allen, into a statue, frozen forever without the ability to move. Of all the Flashes, Wally has been considered the most powerful. While Barry's status as the engine of the Speed Force technically makes him more important, he doesn't have the power or the skill to use it as Wally does. In a contest of who is more powerful, Wally should represent the Flashes. He's the best Flash, and he's also the current main Flash.
Reverse-Flash Vs. The Flash
So, when comparing who is more powerful between Reverse-Flash and Wally West, it's key to look at their greatest feats. Reverse-Flash's is easily his ability to change time. He recreated the history of his life, going back in time and killing everyone who angered him in even the slightest way. He then went back to the past and used those same power to ruin Barry Allen's childhood. This display of pettiness took power unlike any that any other speedster had ever demonstrated. It's the kind of feat that only gods have pulled off, and it lets Reverse-Flash join the rarefied air of villains like Lex Luthor, the Joker, and the worst archenemies of them all.
Wally West has several great feats, from outrunning the Black Flash — and the Black Racer — to robbing Inertia of his ability to move, but his greatest feat comes from his first battle against Zoom. Hunter Zolomon gained the power to control the flow of time around himself when he tried to use the Cosmic Treadmill to go back in time. This made him impossibly fast. Wally couldn't keep up with Zoom because there was no way he could move as fast as Zoom could bend time. However, Wally was able to dig deep and finally gained the power to use the Speed Force to actually move faster than Zoom. This isn't a matter of speed — Wally was such a master of the Speed Force that he used it to move faster than time itself, which is a rate of movement that is basically impossible.
Wally West Is More Powerful Than Reverse Flash
In a similar contest of powers, Barry Allen would lose to Reverse-Flash. Barry has always beaten Reverse-Flash, but he's not actually more powerful than Eobard Thawne. Barry is ridiculously skilled and powerful, but he can't match someone who can change time at will. Thawne is way more powerful than Barry, but his anger and pettiness hold him back. In fact, it would be easy to assume that Reverse-Flash's mastery of time makes him the most powerful speedster of them all, but he doesn't have the victories that he should.
However, Wally has used the Speed Force to move faster than time. It's not even something that can be called speed; it's beyond speed. Wally West has survived his timeline being collapsed; the Speed Force looks out for him. Wally is the only speedster who the Speed Force has allowed to trump time and the multiverse. There's a good chance that Reverse-Flash couldn't even change Wally West's past because of the way he interacts with the Speed Force. Wally is the most powerful Flash of them all, including the Reverse-Flash.