Quicksilver

Quicksilver was essentially Marvel Comics' answer to DC Comics' The Flash, his power is super-speed.

He is also the son of Magneto although he did not initially know it. He is also The Scarlet Witch's brother. The siblings were initially supervillian members of Magneto's Brotherhood, but they soon reformed and joined The Avengers.

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Quicksilver is also another name for the chemical element mercury.