Thanks, D and Jack. Good to see multiple comments on the same character.
More out-of-the-box thinking as I considered what a speedster would be like if he went nowhere fast, and I came up with this guy:
Meet Nowhere, the hero that gets there fast. Possessing mastery of microscopic velocity, Nowhere can adjust the speed of the molecules in his body to change its state of matter or age himself in any direction at will.