Hunter Zolomon

Hunter Zolomon is a convicted serial killer and a meta-human fromEarth Two. Following the explosion of S.T.A.R. Labs' particle accelerator, Hunter was affected during electroshock therapy by the dark matter emitted, giving him super speed. Following this, he escaped, cleaned himself up and became known as Jay Garrick, operating as a hero known as The Flash, stylized as the Crimson Comet, attempting to instil hope. However, later in his life he became a speed demon, secretly known as Zoom, intent on ripping away this hope. He travelled back in time, convincing Jay to act as his archenemy. Discovering the existence of Barry Allen on Earth One, Jay acted as his friend and mentor, apparently training him to fight Zoom, but instead prepping him for his future self, Zoom. He eventually killed his past self, soon after having his identity revealed to Barry and the team.