Audiences will have to wait a few more years before the MCU greets the Eternals, but that doesn't mean introductions should be delayed until then. Makkari, one of the principle members of the group created by Jack Kirby, is their fastest member, and a being who could provide any speedster with a worthy challenge.
The main difference between this particular character and other heroes with superspeed however, is that the speed actually takes its toll on Makkari over time. Fatigue is a major concern, so while he can speed around without problem most of the time, prolonged use of the power can lead to problems.
That said, when the character gets going, he really gets going. He can fly at more than three times the speed of sound, eclipsing all other Eternals in terms of speed while falling short of Marvel's other cosmic beings.