Max Mercury

Initially an obscure speedster, the character was rebooted by Mark Waid in 1993 in the pages of The Flash and turned into a mentor for Wally West and Bart Allen.

Later, he travelled ahead again, and was active in the 1930s and 1940s as Quicksilver when he acted as a mentor to the fledgling Golden Age Flash and Johnny Quick.

According to Jess Nevins' Encyclopedia of Golden Age Superheroes, "Quicksilver fights the Axis mesmerist Baron Hoff, the circus aerialists the Black Cats, the mad scientist Dr. Morlo, the Human Fly, the Screaming Skull, the Witch Doctor, and the Speed Demons, whose super-speed is derived from special pills".

He spent some years in hiding, but was persuaded by Garrick to return to action against Professor Zoom (who was posing as Barry Allen).

While living with Bart, Max met an aged physician named Helen Claiborne, who turned out to be his daughter from his earlier affair.

Max assists Johnny Quick, Bart Allen and other speedsters in taking the murderous Superboy-Prime to another realm far past the Speed Force.

In The Flash: Rebirth #4, Max has recently been brought back, as Barry Allen helps take him out of the "Negative Speed Force" controlled by Professor Zoom.

He also differs from other speedsters because of his agility; he cannot run as quickly as the Flashes, but he has a greater ability to perform acrobatic stunts and finely coordinated actions than they do.