“The fastest person alive is also the one who overthinks the most — a forensic scientist whose speed can't outrun his fear.”
He draws speed from an extra-dimensional energy source. He can exceed the speed of light and apply it to combat, movement, and time travel.
Vibrates his molecules to phase through solid matter — lets him pass through locked doors or let physical attacks pass harmlessly through him.
At sufficient speed he can travel through time — the same ability that caused the catastrophic Flashpoint timeline split.
The fastest man alive is also the one who overthinks. His actions are instant; his self-doubt is not. Beneath the optimism, the trauma of losing his mother and watching his father wrongfully imprisoned colors every choice he makes.