DC comics has been using the Flash and his ability to run through time, every time they need to reboot or alter the time line. Selling more comics and reusing existing story arch’s but this can also be very confusing for new comic book enthusiast. CW’s Flash is one of our favorite TV shows but by introducing a new set of speedsters each season, it has also confused a lot of viewers, so here is a brief breakdown of the scarlet speedster’s main nemesis throughout the years.
Edward Clarris (The Rival)
First appearing in Flash #104, Edward Clarris was a professor who attended the same university as the golden age Flash (Jay Garrick). He managed to recreate the formula which gave the Flash his powers, the formula which he called Velocity 9 gave its user’s temporary super speed. After being discredited by the scientific community, Clariss becomes a criminal donning a darker version of the Flash’s suit with a mask over his head. He was caught and imprisoned by the flash as the effects of Velocity 9 wear off. He inexplicably regains his speed in JSA #16 and in a battle against the Flash, reaches light speed and vanishes into the speed force. Jonathan (Jhonny) Sorrow retrieves Clariss from the Speed Force, 50 years after his disappearance. The Rival, driven insane in the Speed Force, races across the country on a killing spree. The Flash realizes that the Rival's path across the country spells out Clariss' name and the final murder will be Jay's wife Joan Garrick, Jay absorbs the Rival's speed before he can kill Joan.
Eobard Thawne (Professor Zoom)
One of the most confusing origins, Eobard Thawne’s origin has been altered and rebooted several times. Which is why we will stick to the most popular Post-Crisis and Zero Hour origin. First appearing in Flash #139, Eobard Thawne was a fanatical fan of the silver age Flash (Barry Allen) from the 25th century, and was obsessed with meeting him. He replicated the electro chemical bath which gave Barry his powers and underwent surgery to make him look like the Flash, Eobard traveled back in time using the Cosmic Treadmill (Created by the Flash, the Cosmic treadmill allowed the speedster to travel to specific points in time) to meet the Flash. However, the machine had broken down over the centuries, and Eobard became mentally unstable upon arriving several years after Barry's death at the Flash Museum, where he discovered that he was destined to become "Professor Zoom”, and die at the hands of his idol. As a result, his mind, already disoriented by the stress of time travel, convinced himself that he was Barry Allen, but his true identity is eventually revealed due to his violent nature. When Thawne (as "Barry") attacks Central City for "forgetting him", he is defeated by Wally West and sent back to the future with no memory of the incident. Eobard also finds a time capsule in the 25th century containing the Flash's costume, and was able to use a Tachyon device to amplify the suit's speed energy, giving himself the abilities of the Flash as long as he wore it. In the process, Thawne reversed the colors of the costume, the suit becoming yellow, the boots and lightning bolt highlighting the red color, and the chest symbol's white circle becoming black. He was eventually stopped by Barry, who had travelled forward in time to stop the atomic clock in the time capsule from exploding.
Thawne desperate for revenge appears in the speed force and revives Barry who sacrificed himself during the crisis event, and temporarily makes Barry the Black Flash (Negative Speed force, which kills any speedster he touches, which Barry discovers when he accidently vaporizes Savitar, with his touch).Worried that he would killing Wally, Jay and Bart with a touch decides to return to the speed force during which Barry generates enough positive energy to burn off the negative speed force.
Unable to defeat Barry, he tries to stop him from ever becoming the Flash, which is when he realized that if Barry never became the Flash he would never become the reverse Flash and decides to ruin his life instead and goes back in time, killing Barry’s mother.
Barry goes back in time to save his mother creating Flashpoint, an event that changed history. During this time Thawne kept running in the time stream, making him a living paradox he could be the reverse Flash irrespective of him killing the flash in the past present or future, Thomas Wyane (Batman within Flashpoint) kills Thawne and Barry runs back in time and attempts to reset the timeline once again, allowing his mother to die to create the New 52 merging wild storm vertigo and dc universe together.
Hunter Zolomon (Zoom)
First appearing in The Flash: Secret Files & Origins #3, Hunter Zolomon came home to find police surrounding his house. His father, a serial killer who had killed six young girls, had killed his mother when she turned him in, the day he was to leave for college. His father was killed by the police when he refused to surrender. To stop people like his father, Hunter became obsessed with understanding the criminal mind. He studied psychology and criminology in college and joined the FBI with his girlfriend, Ashley (whom he later married), specializing in low-level costumed criminals. One case resulted in Ashley's father's death, as Hunter erroneously thought the criminal they were after was incapable of facing his adult life, and would not use an "adult" weapon like a gun. Ashley left him shortly afterwards, and he was fired by the FBI. The case left Hunter with a damaged knee. He moved to Keystone City and got a job as a profiler, working with the police in its Department of Metahuman Hostilities. Hunter's work put him in constant contact with the Flash, Wally West, and they became good friends. Although his insight was critical in solving a number of cases, he resented being stuck behind a desk. Hunter was severely injured in an attack by Gorilla Grodd in Iron Heights when Grodd staged a mass prison break, and was left paralyzed from the waist down. He asked Wally West to use the time-traveling cosmic treadmill in the Flash Museum to prevent this, West refused, saying that he could not risk damaging the time stream. Hunter, believing that Wally disregard such fears for the sake of their friendship, broke into the museum and tried to use the treadmill himself. The resulting explosion destroyed the museum, gave Hunter the use of his legs again and shifted his connection to time ("derailing" him from the time stream), giving him super speed and making him one of Wally’s greatest foes.
The origin and costume of Zoom, in the CW universe varies greatly, where he is a serial killer on Earth-2 who was captured and subjected to electroshock therapy at a mental hospital. While he was being treated a particle accelerator exploded, giving him his powers.
Thaddeus Thawne II (Inertia)
First appearing in Impulse #50, President Thaddeus Thawne sought to recruit Bart Allen in his revenge campaign against the Allens. When that failed, Thawne mixed Bart's DNA with Thawne genetic material to create a speedster clone whom he named Thaddeus Thawne. He was trained to hate Impulse and tuned into a sadistic sociopath, who used steroids to boost his speed. After failing to defeat Bart Allen by himself, Inertia began to gather a Rogues Gallery of villains to team up against Flash. Inertia, in a plan to steal the speed force energy for himself, manipulated the Rogues into battle with Bart. As a depowered Bart fought valiantly against the combined might of the Rogues, he saw the spectre of the Black Flash, and died as Iris Allen and Valerie Perez were left to mourn him. Wally West went after Inertia, hunting him down. As Inertia antagonized him, Wally reduced his Inertia's speed to the point that he is completely immobile, becoming a living statue. Inertia was then placed in the Flash Museum facing the tributes to Bart Allen, forced to look at the man that he could never be. Zoom frees Inertia from his frozen state. He teaches him how to tap time as a power source. The Rogues come after Inertia for misleading them into killing Bart, as he was just a kid. Inertia decides he is Kid Zoom. When Zoom objects Inertia removes his powers by "unraveling" time, leaving Zoom as paraplegic Hunter Zolomon. He also hurts Libra. The Pied Piper freezes Inertia, which leaves him vulnerable for the Rogues to stop, and kill, Inertia in a similar way that Bart died.
Danny West (Reverse Flash)
First appearing in Flash Vol 4 #0, Daniel West's mother died giving birth to him, a fact for which his father William never forgave him. This also drove his father to become an abusive alcoholic. His sister Iris protected and supported him until the day his father went too far, and an angry Daniel pushed him down the stairs, crippling him for life. When he realized that Iris' opinion of him would change forever as a result of those actions, Daniel ran away from home, blaming his father instead of himself for what happened. Turning to crime he was captured by the Flash and imprisoned for five years. While he struggled to make it on his own, he was captured by Gorillas when they attacked the Gem Cities. When he was rescued by the Rogues he learned that they still intended to rob those they had saved. In his attempt to escape them, he crashed into Dr. Elias' stolen monorail car, which was powered by a Speed Force battery. The accident imbued him with the ability to turn back time, but that power was dependent on the Speed Force charge in the battery. Unlike other speedsters he wore armor made of the monorail fragments that he could control on his will, Wanting more than anything to go back in time and change his relationship with Iris by killing his father, Daniel dubbed himself the Reverse-Flash and began murdering those who had been touched by the Speed Force in order to drain them of the energy he would need to go back in time far enough to change his own past. In a series of events he causes himself more trauma and Daniel gave his powers up to the Flash to let him fix his mistakes.
A Cold War pilot whose real name is unkown, was to test a supersonic fighter jet. As he reached top speed, his plane was struck by what appeared to be lightning and gave him super speed. As he went down in hostile territory, he discovered his new ability and used his speed to defeat his enimies, he became obsessed with speed, naming himself after Savitr, the Hindu "god of motion", and dedicating his life to unlocking its secrets. As Savitar studied, he discovered new powers that no other living speedster has mastered. He can protect himself in a null-inertia force field, give speed and kinetic energy to objects or people, even those in a rest state, and could also heal his own injuries almost instantly.
He then used Lady Flash (Ivana Christina Borodin Molotova) powers as a catalyst to strip most of Earth's speedsters of their link to the Speed Force, transferring their speed to the Thunderbolt Agents (A cult of Savitar’s followers). He sent a few of these agents to attack Wally West. When these proved ineffectual, he sent more to kill the other speedsters: Impulse, Jay Garrick, Johnny & Jesse Quick, XS and Max Mercury.
Fortunately, Wally’s direct link to the Speed Force prevented Savitar from stealing his speed, and a coalition of all the speedsters he had tried to kill, foiled his plans. Hell-bent on at least destroying Flash’s world in retribution, he led the Flash on a worldwide race of destruction, until Flash merged Savitar with the Speed Force. Savitar was able to escape from the Speed Force. He was run down by the recently returned to life Barry Allen (then effected by negative energy, turning him into the Black Flash) however, when Barry touches him, Savitar disintegrates, leaving only a pile of bones.