The Flash can outrun just about anyone or anything in the DC Universe, but there’s one thing that absolutely no one can escape: death itself.

That’s where the Black Flash comes in. When a speedster’s life is at an end, this seemingly omnipotent being appears to bring their body back into the Speed Force. People like Barry Allen and Wally West may have been given an incredible gift - but said gift comes with a pretty hefty price tag. No one knows where the Black Flash came from, or who it serves, but one thing is for certain: when it appears, the death of a speedster follows.

All things considered, it looks like the Black Flash will have a bigger role as the CW’s Arrowverse continues to expand - which means that now is the perfect time to take a look at the Scarlet Speedster’s deadly doppelganger! Here are 15 Things You Need To Know About The Black Flash:

15. It first appeared in Flash Vol. 2 #138 (June, 1998)

For such an important aspect of the DC Universe’s metaphysical lore, it's surprising that the Black Flash didn’t make his debut until the late ‘90s. The Flash had already been tearing his way through Central City for decades, and Barry Allen (the second speedster) had already died during the events of Crisis of Infinite Earths.

The Black Flash’s creation can be credited to Mark Millar, Ron Wagner and Grant Morrison - three names that any longtime comic book fan will recognize. It’s telling that, even though the team created one of the most powerful entities in the DC Universe, the Black Flash is still one of their smaller accomplishments.

On top of that, in a somewhat surprising move, DC has been relatively conservative when it comes to using the Black Flash. Though the speedster did make a number of appearances throughout different Flash books, the Black Flash never outstayed its welcome or appeared too often. As a result, it hasn't lost any of its impact: whenever readers see the Black Flash, they know something big is about to go down.

14. Max Mercury first discovered the Black Flash

Due to its delayed debut, the third Flash (Wally West) would be the first to go toe-to-toe with the Black Flash. The storyline wasn’t particularly long, but its impact can still be felt throughout the different Flash stories today.

After Wally West fully accepted the mantle of the Flash, Max Mercury and Jesse Quick discovered the presence of the Black Flash. In an attempt to save Wally’s life, the duo stopped him and explained their findings: a black smudge in the background of a photo. The same smudge had appeared in a similar picture taken before Jesse Quick’s father had been killed, and Mercury was worried that the smudge’s reappearance meant that Wally’s death was inevitable.

To their surprise, the smudge had disappeared from Wally’s photo. It seemed like the duo’s plan had worked - though, in reality, the Black Flash had merely switched targets. Instead of taking Wally back to the Speed Force, it took his soon-to-be fiance Linda Park, apparently killing her in the process. It was a chilling first encounter, and one that proved how dangerous the Black Flash could be.

13. It lost a race to the end of time

Not to be deterred, the Black Flash returned for Wally shortly after taking Linda into the Speed Force. It was here that the real battle began: a race between the Fastest Man Alive and the Black Flash.

The race is a classic example of how ridiculously powerful DC’s heroes can be. Other heroes with super-speed may be fast, but few have ever come close to actually traveling through time. Not only did his race against the Black Flash prove that Wally was as fast (if not faster than) his predecessors, it also proved that time travel wasn’t always a one-way trip.

Eventually, both Wally and the Black Flash began accelerating forward through time - in the blink of an eye, the two speedsters raced millions of years into the future. Though it initially appeared as if the Black Flash’s limitless stamina would put an end to the race, the two reached the literal end of time before it was able to catch up to Wally - and, at the end of time, death has no meaning. The Black Flash dissipated, and Wally returned to the Speed Force for Linda.

12. It isn’t actually Death incarnate

Even when it was first revealed, it wasn’t all that hard to figure out what the Black Flash’s purpose was. Though the original story never really touched on its origins, the Black Flash was clearly a representation of death. That being said, like much of the publisher’s continuity, DC’s concept of ‘death’ and its representation gets complicated pretty quickly. For anyone interested, Neil Gaiman’s Sandman series touches on many of the metaphysical aspects of DC’s expanded universe, including the nature of Death (and it’s a phenomenal read, too).

The thing about the Black Flash is that it’s not specifically Death itself. Yes, it does act as an agent for the end of life in regards to speedsters, but it doesn’t represent the physical incarnation of the concept. Think of it more as the Speed Force’s extremely aggressive courier: when it’s time for a speedster to return to the source of their power, the Black Flash is sent to retrieve them.

11. Its origins are still unknown

Arguably, the worst part about the Black Flash is that the heroes of the DC Universe know very little about it. During the Flash’s first encounter with it, the Black Flash acted more like a force of nature than an actual villain - and that trend continued whenever it reappeared. While it’s easy to assume that its motivations are simply for the passage of speedsters back into the Speed Force, its origins are harder to decipher. Though DC has provided some hints as to why Death needs an agent devoted solely to speedsters, nothing’s ever been confirmed one way or another.

One theory suggests that Death itself simply can’t keep up with speedsters, and the Black Flash acts as a way to cover that loophole. Others have inferred that it may be a part of the Speed Force itself, and that its presence simply guarantees that the energy present in speedsters returns to where it belongs.

Both theories make sense (in a crazy, convoluted, DC kind-of-way), but until the writers come up with something more concrete, the true nature of the Black Flash will be a mystery.

10. It isn’t always the cause of death

The first battle against the Black Flash was, for the most part, a one-on-one test of endurance. Wally was forced to run faster than anyone ever had before, to the point where he nearly killed himself. Throughout the entire storyline, the Black Flash made itself known as a very serious, very intimate threat.

That being said, not every encounter with the Black Flash has been the same. In many of its subsequent appearances, the Black Flash is more of a passive observer than anything else.

Take Bart Allen, for instance: after being de-powered and forced to face off against the Rogues, the Black Flash appeared before the weakened speedster. However, instead of chasing after Bart as it did with Wally, the Black Flash merely made its presence known. Granted, it wasn’t any less intimidating than during its first appearance, but it was the Rogues that eventually killed Bart Allen. The Black Flash was there to collect his remains, but it wasn’t the cause of death.

9. It’s more of an bystander than a villain

Bart Allen wasn’t the only speedster to see the Black Flash before his death, either. In fact, the Black Flash is more often a passive observer than an active antagonist: though its debut set the stage for future conflicts, the storylines and retcons that followed ensured that the Black Flash was far less of a traditional villain.

After its first appearance, it was revealed that the Black Flash would appear as a speedster was about to die. For most speedsters, the Black Flash was more of an omen than anything else: as previously mentioned, it appeared before Bart’s death at the hands of the Rogues, though it was never directly involved. Similar occurrences have happened to a number of other speedsters. Photos of Johnny Quick and Barry Allen featured the same black smudge that foreshadowed the Black Flash’s first appearance, and even Max Mercury caught a glimpse of the black-clad speedster during his near-death experiences.

It’s an admittedly interesting (if sadly under-utilized) twist for the villain: despite its horrifying exterior, the Black Flash is more of a sign of impending doom than anything else.

8. It doesn’t dress like a villain

When it comes to being a villain, it’s all about looking the part. For the Flash’s various speedster enemies, that usually means one thing: some sort of play on the Scarlet Speedster’s classic threads, complete with a backwards version of the iconic lightning logo. Reverse-Flash may have made it popular, but he’s far from the only speedster to invert Barry Allen’s classic costume.

One might assume that, following the example of its predecessors, the Black Flash would feature similar fashion statements...but that’s not actually the case. For whatever reason, its ‘uniform’ is simply a blackened version of the original - complete with the standard lightning bolt logo.

That might not sound like much, but fans have theorized that the Black Flash’s uniform is a subtle sign that it’s not actually a villain. It’s definitely an unconfirmed fan theory, and the Black Flash’s actions speak louder than its choice in costume, but it adds an interesting layer to the mythology of the character.

7. It possesses incredible power

As if super-speed and the ability to kill weren’t enough, the Black Flash boasts some seriously powerful abilities. During its second attempt to capture Wally West, the Black Flash not only gave every living speedster at the time a run for their money, but also managed to freeze time itself.

Though the specifics of this power are never explicitly stated, the Black Flash managed to stop time for all but the fastest beings on the planet. The result was an entire airport of normal humans that simply stopped, and the only people that were still able to move were all speedsters. Even worse was that, despite such a display of power, stopping time seemed to have no impact whatsoever on the Black Flash’s overall speed.

And that was just the start: the Black Flash also possesses the ability to enter and leave the Speed Force at will, is seemingly immortal, and can render itself intangible. Most villains in the DC Universe have a fatal weakness - though that doesn’t seem to apply to the Black Flash.

6. It draws energy from the Negative Speed Force

The very nature of the Speed Force seems to be in constant flux. Various storylines and continuity reboots seem to change the Speed Force’s nature every few years, and keeping up with the source of the speedsters’ powers can be an absolute nightmare.

On top of all that, with so many villains acting like inverted versions of the Flash, it only makes sense that the Speed Force would have its own doppelganger. Dubbed the ‘Negative Speed Force’ by Eobard Thawne, this secondary power acts as the total opposite of the original Speed Force. Judging from numerous hints and callbacks throughout the years, this is where the Black Flash draws his incredible speed from.

To be perfectly honest, nothing has been set in stone. Given that the Black Flash seemingly acts as a tool of the Speed Force, the idea that it would draw its power from the Negative Speed Force seems strange. On the other hand, both Black Flash and the Reverse-Flash generate red lightning when using their powers, a trait that’s been associated with the Negative Speed Force.

Both theories do make sense in the overall continuity...though no one will know for sure until the Black Flash makes his long-awaited return.

5. It’s affected by time travel

Time travel is a huge part of the Flash’s history. Some of the biggest moments in the character’s history have been defined by traveling through time to rewrite history, and writers have been using it as a story device more and more as the character has evolved. Even the Black Flash’s first appearance focused heavily on this trope, to the point where Wally West found the literal end of time.

What’s interesting is that the Black Flash isn’t immune to the effects of time travel. Though time travel has never been used directly against the Black Flash, various retcons and continuity changes have proven that its work can be undone by manipulating the fabric of time. Whereas the ‘time wraiths’ of the CW TV series are a directed response to time travel, the Black Flash’s purpose seems to center around the death of a speedster and nothing more. As such, it - like most other beings in the multiverse - is susceptible to the machinations of both time and time travel.

4. Don't confuse it with Eobard Thawne’s zombie...

So, to recap: the Black Flash, even though it looks like a darkened version of the Fastest Man Alive, has no real affiliation with the Flashes themselves. Instead, it acts like a version of the Grim Reaper specifically designed to take down those with a connection to the Speed Force - as a result, it’s not necessarily evil, even if it takes on an antagonistic role by default.

This is where things get confusing. The Blackest Night storyline centered around a number of the DC Universe’s dead heroes and villains returning to life as black-clad zombies. One of these zombies is none other than Eobard Thawne, otherwise known as the Reverse-Flash - who, unsurprisingly, is wearing a black version of the Flash’s classic costume.

Looking at the undead Reverse-Flash and the Black Flash is, to put it lightly, extremely confusing - especially considering the re-animated Thawne called itself the ‘new Black Flash’. However, despite the fact that they look nearly identical, the Black Flash had absolutely nothing to do with Blackest Night, and an alternate (living) version of Thawne eventually returned with his classic yellow-and-red threads.

3. ...Or the New Gods' Black Racer

It’s been established that the Black Flash is a black-clad being with unimaginable power that acts as a manifestation of death. Now, to make things a bit more confusing: the Black Racer is a black-clad being with unimaginable power that acts as a manifestation of death. Both cross paths with speedsters on a regular basis, and neither are truly evil; they simply act as a force of nature.

To be fair, the Black Racer’s primary focus isn’t on speedsters, but rather the New Gods of Apocalypse. With that being said, the Black Racer is no stranger to antagonizing those with super-speed: the Black Racer was seen chasing Barry Allen out of the Speed Force during the events of Final Crisis, and Bart Allen played host to the Prime Earth version of the Racer for a short time.

At the very least, the Black Racer is a bit easier to separate from the Black Flash simply because of its method of transportation. The idea of running from death is somewhat terrifying on its own...but some of the impact is lost when death slides around on skis.

2. It hasn’t been seen since Flashpoint

The worst part about a being like the Black Flash is that, no matter what, it’s always there. It may not be at the forefront of any given conflict, but every speedster knows that the Black Flash is out there waiting for its chance to return them to the Speed Force.

What's weird is that the same thing could be said for comic book fans. It doesn't matter if a character lives or dies - at a certain point, it's only a matter of time until they return.

And it's been quite some time since the Black Flash made an appearance. It was last seen returning to the Speed Force after a run-in with Barry Allen and the Reverse-Flash, and that was during the Flash: Rebirth storyline in 2009. A new take on a 'Black Flash' briefly appeared during the Darkseid Wars event, but that wasn't the genuine article. Simply put, it’s been years since our heroes has had to deal with the Black Flash...meaning that a return may be right around the corner.

1. Barry Allen briefly became the Black Flash

Despite the fact that he spent quite a few years being dead, Barry Allen is almost universally accepted as the Flash. Wally West may have been the Fastest Man Alive for quite a while, but between Barry’s return in the comics and the popularity of the CW television series, it’s clear that one Flash stands out from the rest. So...what happens when the biggest Flash of them all becomes an agent of Death?

During the Flash: Rebirth storyline, Barry Allen comes into contact with the supposed remains of the Black Flash. This in turn imbues Barry with the abilities of the Black Flash, including the desire to kill those connected to the Speed Force. In an effort to undo the transformation, Barry re-enters the Speed Force, which ends up pulling the Black Flash’s essence from his body.

This wouldn’t be the only time that Barry Allen became a force of death: during the Darkseid Wars crossover, Barry is merged with the Black Racer, and becomes a hybrid being that essentially acts as a new version of the Black Flash. Unsurprisingly, Barry is soon separated from the Black Racer and returns to normal - and the ultimate fate of the Black Flash (if it even still exists) is still unknown.

Basically, if there’s one thing that fans of the Flash should take from this list, it’s that being friends with Barry Allen probably won’t end well for anyone.