Reverse Flash (Tom Cavanagh)

Eobard Thawne, nicknamed the Reverse-Flash by Cisco Ramon, is a villain from the future who traveled back into the past to kill Barry Allen, although it is unclear if he intended to kill the adult Barry who was there or the young one. Under unknown circumstances, he ended up killing Nora Allen instead.

Assuming Harrison Wells' identity, he forged a life for himself as a scientist at S.T.A.R. Labs eventually becoming the Director and pushed through for the creation of a particle accelerator to ensure that Barry Allen becomes the Flash and teach him to increase his speed so that he could return to his own time in the future.

Speed Force Connection

 * Superhuman speed: Eobard can move stupendously fast and is significantly faster than Barry currently. Barry said that he's so fast that he could kill everyone in the police precinct in seconds. He is so fast that he can be at two places at once. His bodily control can also vibrate his entire body to mask his body from others clearly perceiving it and even distort his vocal cords to disguise his voice. However he states his speed comes and goes and he is unable to control when it does. Likewise, it appears to be directly involved with his ability to walk, as once his speed became unusable, his legs quickly gave out and he collapsed to the floor.
 * Rapid cellular regeneration: Eobard's fast healing was displayed when the wounds inflicted upon him had vanished almost instantly after putting on the tachyonic device on his suit. Without the tachyon device, he healed completely in an hour and not instantly. Harrison's wounds from being attacked with the force of a speeding car by the "Man In Yellow" were completely gone without a trace afterwards, which he covered up by isolating himself to avoid speculation of any kind.
 * Extreme force generation: By building up enough kinetic force in his body, Reverse-Flash is able to deal very punishing blows. Even Barry Allen with his accelerated recovery abilities was quickly pummeled to the point he was unable to fight back. He generated enough force in his movements to almost completely breach a radioactive force field though he only managed to grab Harrison and pull him in to beat him up and leave him severely injured. Harrison's injuries looked similar to that of a person hit by a car, suggesting that he was attacked with similar force.
 * Accelerated perception: Eobard's speed also extends to his senses and mental capacities, allowing him to take in information and process it at much faster rates than a normal human. This ability allows Harrison to see the world as if it is in slow motion, which, combined with his physical speed, lets him perform thoughts and actions long before a normal human around him could even perceive them. Even Harrison was having troubles keeping up with how fast Shawna's cells were moving when he was trying to look at them.
 * Intangibility: Eobard can move any part of his body so fast that he can phase himself through people or objects. When used on a person, it can have lethal power, is Mason Bridge instantly died from a gapping wound in his chest.
 * Speed mirage: Eobard can move so fast he can create lifelike "after-images" of himself, allowing him to literally be in two places at once. Thawne used this ability to appear as the Reverse-Flash, seemingly beating up Harrison almost to death.
 * Time Travel:

The Flash
Season 1
 * "Pilot"
 * "Fastest Man Alive"
 * "Things You Can't Outrun"
 * "Going Rogue"
 * "Plastique"
 * "The Flash Is Born"
 * "Power Outage"
 * "Flash vs. Arrow"
 * "The Man in the Yellow Suit"
 * "Revenge of the Rogues"
 * "The Sound and the Fury"
 * "Crazy for You"
 * "The Nuclear Man"
 * "Fallout"
 * "Out of Time"
 * "Rogue Time"
 * "Tricksters"