Roscoe Hynes (Earth-1)

History
Roscoe Hynes was an air pilot. He was hit by the same particles from the particle accelerator that turned Barry Allen into the Flash, but instead of giving Roscoe his own powers, it trapped him inside the Speed Force.

Within the Speed Force
Cisco Ramon once received a vision of Hynes, trapped in the Speed Force, calling out for help. Cisco then used his powers to send Barry into the Speed Force and save Hynes. After telling Barry of how he became trapped in the Speed Force, Hynes tried to kill Barry. Barry managed to defeat Hynes, and left him in the Speed Force.