Time travel is a common trope in science fiction, and while many heroes have this capability, it takes a particularly malevolent mind to use such powers to selfish ends. Some of the greatest supervillains in comic books count time travel among their arsenal of dastardly tricks, with many of them unafraid to bend time and space to their will. <p>Here are ten of the most despicable villains ever to manipulate the time stream to their own ends, often showing disregard for the effects of their actions on the world around them, or simply refusing to let something like the passage of time prevent them from reaching their goals.
Nimrod is a mutant hunting robot built from technology derived from the original Sentinels. Hailing from the "Days of Future Past" timeline, and virtually indestructible, Nimrod followed Rachel Summers into the past, causing no end of destruction and trouble for the present day X-Men. <p>Eventually, he was absorbed by Master Mold, the gigantic core Sentinel. When both were sent through the Siege Perilous, a dimensional gateway that erases the identity of those who travel through it, Nimrod and Master Mold merged into the being known as Bastion, a fully sentient, fully evolved Sentinel who has been destroyed and rebuilt using pieces of Nimrod's previous body several times.
Though the man known as Epoch, or the Lord of Time, was one of the biggest nuisances to the Justice League in their early days, he's also caused numerous problems for characters like the android Hourman, the Legion of Super-Heroes, and has even shown up in the post-apocalyptic world of Kamandi. <p>Epoch started out with good intentions; gaining his time traveling powers in the year One Billion AD, he built a prison called Timepoint that existed outside of the time stream, and began imprisoning the world's greatest villains there. Somewhere along the way, he began menacing the Justice League, and eventually became an out and out villain. It's unclear which of his adventures, if any, are canon, since he died in his final appearance, which predates the New 52.
Per Degaton was once a normal man who was employed by a scientific group known as the Time Trust, who were dedicated to finding a way to travel to the future to obtain technology to help end WWII. When the Time Trust sent the JSA into the future, Degaton sabotaged the anti-bomb shield technology they brought back. Degaton fled the Time Trust, embarking on a career as a mad scientist and terrorist in pursuit of time travel technology of his own. <p>In one of his attempts to build a time machine, Degaton enlisted the help of a scientist named Professor Zee, who successfully created a time machine. Degaton double crossed Zee, intending to steal the machine for himself, but accidentally sent it into the future. Forced to wait forty years for the machine to re-appear, Degaton continued his life of crime. When the machine re-appeared, it contained not only the dying Professor Zee, but a "chronal duplicate" of Degaton himself. <p>The older Degaton disintegrated upon contact with the chronal duplicate, causing his robotic partner Mekanique to kill the duplicate. It is later revealed, however, that thanks to the magic of time travel, the duplicate continued to exist, controlling the time machine prior to his death, leading him to become a longtime foe of the JSA until much of their history, and presumably Degaton's, were successively wiped away by multiple reboots and retcons.
Time travel in the DC universe is a dicey proposition at best thanks to nearly constant reboots, crises, and retcons, and none have suffered as much as the Time Trapper. The Time Trapper's origin has fluctuated so wildly, and so frequently, that it's actually a little unclear who he - or she - actually is. Over the years, the nemesis of the Legion of Super-Heroes has been revealed as a future version of Cosmic Boy, a Controller, a woman named Lori Morning, as the embodiment of the force of entropy, as an alternate timeline given sentience, and, in his most recent appearance, as an older version of Superboy Prime. <p>Whoever the Time Trapper may actually be, he has menaced the Legion of Super-Heroes almost as long as they've been around, and has also gone up against Wonder Woman, and even appeared as a villain on The Super Friends. Most of his history was wiped out during <i>Zero Hour</i>, and he didn't appear again until <i>Final Crisis: Legion of Three Worlds</i>, when he was revealed as Superboy Prime. Time Trapper hasn't appeared since DC's <i>Flashpoint</i> reboot, but as they say, it's just a matter of time.
Though Immortus and Kang are technically both actually Nathaniel Richards, they aren't the same person. You see, Immortus and Kang hail from diverging timelines. One of the pitfalls of time travel, at least in the Marvel universe, is that too much of it can result in multiple futures, some of which are often at odds with each other. In Immortus's timeline, he is a much older version of Kang who, weary of the cost of constantly doing battle and dealing with the deaths of his consort Ravonna, and son Marcus, joins a group called the Time-Keepers who are dedicated to preserving the integrity of important timelines. <p>Immortus's greatest conflict with the Avengers actually stemmed from a desperate struggle against his younger self, when Kang began wreaking havoc on the timestream. Eventually, Immortus turned on his masters, the Time Keepers, and was subsequently killed, though they resurrected him almost immediately.
Bishop is unique to this list in that he began his time-traveling career as hero, sent back in time from a future where mutants are hunted to ensure that Trevor Fitzroy, a villainous mutant, did not kill the X-Men, and to prevent a traitor from betraying the team, leading to the future from which he hailed. After years spent fighting alongside the X-Men, Bishop finally turned on the team and attempted to kill Hope, so-called mutant Messiah, nearly killing Professor X in the process, and becoming the traitor he sought to stop. <p>When fellow time-traveler Cable saved the child, fleeing into the timestream, Bishop followed, pursuing the pair through numerous eras as Cable raised Hope as a soldier and a survivor. Bishop wreaked devastation across numerous timelines in his hunt for Hope, justifying his actions by dismissing the millions of deaths he caused as people who didn't actually exist. Bishop finally teamed with Cable's evil clone Stryfe, himself a time-traveler, to track Cable and Hope to the present day. In their final confrontation, Bishop killed Cable, but a now mature Hope damaged Bishop's time-travel device, stranding him in the far future. Bishop later returned, regaining some of his former heroism by helping save Hope from Stryfe.
DC Comics actually had two characters named Chronos. The first was David Clinton, the arch-enemy of the Atom, Ray Palmer. Originally, Clinton was simply an engineer who used his intellect to commit crimes using time and clock themed weapons. He long sought to actually perfect time travel, and eventually began stealing not for his own fortune, but to obtain money to continue his research. Eventually, he achieved his goal, but still seeking more power, struck a deal with the demon Neron that eventually lead to his downfall. David Clinton reappeared in the New 52 as an agent of A.R.G.U.S. specializing in time travel. <p>The second Chronos, Walker Gabriel, was actually something of an anti-hero. He possessed David Clinton's time travel technology after Clinton's death, and acted as either hero or villain depending on his need. Eventually, Gabriel erased his own existence to save his mother's life, but due to the circumstances of time travel, a version of Gabriel remained. He was later killed by fellow time traveler Per Degaton, but when Degaton's scheme failed, he was returned to life. Walker Gabriel was last seen as a denizen of Limbo during <i>Final Crisis</i>.
As tends to happen with time-travelers, the true identity of the despot known as Monarch remains a little confusing. Originally conceived as a future version of the hero Captain Atom, driven to conquer the world as the main villain of DC's <i>Armageddon 2001</i> crossover, his identity was changed mid-story when the secret leaked. Instead of Captain Atom, Monarch was revealed to be Hank Hall, AKA Hawk of Hawk and Dove. Years later, in the disastrous limited series <i>Countdown</i>, Monarch resurfaced with his original origin intact, as a future version of Captain Atom. <p>Before that, when he was still technically Hank Hall, Monarch was defeated when he traveled into the past to defeat Waverider, a being he empowered to travel time, who betrayed Monarch and attempted to decipher his true identity. Later, Hank Hall became known as Extant, a time-traveling menace who caused yet another rebooted version of DC continuity in the <i>Zero Hour</i> mini-series. Extant went on to challenge a reformed JSA, but was defeated by the time-traveling android Hourman.
Dr. Doom is kind of a renaissance man of villainy. Not only is he possessed of the greatest intellect in the Marvel universe, limited only by his own hubris, he is also the second greatest sorcerer of our world, and the inventor of time travel technology. Doom has used this technology for numerous purposes, but has traditionally refused to use it to defeat his hated nemesis, Reed Richards, instead insisting that he must best Richards as an intellectual, and not through such underhanded means. <p>Though time travel may not be his primary gig, Doom is an important time-traveler nonetheless, having actually devised the technology from which all other time travel devices in the Marvel universe are derived. Many, many others have used this technology, including Reed Richards's father, Nathaniel Richards, and his namesake, the villainous Kang. Even the Beast used Doom's technology to travel into the past, and bring younger versions of the original X-Men to the present day.
Kang is the unquestioned master of time-traveling villainy. In his numerous guises, such as Rama-Tut, Blue Man, Victor Timely, and the Scarlet Centurion, he has traveled back to the present day from the 30th century time and time again to test his mettle against the greatest warriors of all time; the Avengers, the Fantastic Four, and other of the Marvel universe's finest heroes. <p>Kang has always traditionally refused to use his power over the time stream to best his enemies before they gain their power, but in his recent appearance in <i>Uncanny Avengers</i>, he seems to have abandoned this code of honor. Kang's strength as a warrior is not to be denied. He has conquered Earth in numerous ages, even adopting strange aliases and identities to do so. Still, he has never bested the Avengers. <p>Kang will square off with Black Bolt and Medusa over the fate of their son, Ahura, in the upcoming <i>Uncanny Inhumans</i> series.