FOR THE PURPOSE OF THIS COMPARISON I WILL BE USING Flash II (Barry Allen)
The Flash–> Barry Allen’s mother was killed when he was a child & his father was convicted of her murder. The strong belief that his father was innocent gave Barry a strong sense of justice which is what led him to be a forensic scientist before becoming the flash in a freak accident where lighting struck his lab covering him in electrified chemicals making him the flash.
Quicksilver--> The son of magneto Quicksilvers speed comes from a genetic mutation. Winner– FLASH
The Flash–> Member of the Justice League, Sidekick with same powers (Wally West/Kid Flash)
Quick Silver–> Member of the Brotherhood of Mutants & The Avengers
Winner–Quick Silver (Two Powerhouse teams)
The flash–>Speed of light
Quick Silver–> Speed of sound
Winner–The Flash is faster
The Flash–> Nephew (Wally West |3rd flash|); Grandson (Bart Allen |4th Flash|)
Quick Silver–> Father (Magneto), Sister (Scarlet Witch), Half Sister (Polaris)
Winner– Quick Silver (Family Members with various abilities)
The Flash– Can do everything quicksilver does + vibrate his bodies molecules enough to become invisible to the naked eye & cross through walls.
Quicksilver– Can also think at superhuman speed, Can create cyclone type winds, run up walls, cross bodies of water.