Who exactly is Black Flash?

So is Black Flash actually a person who can fight other heros or villains and has his own superpowers or is he more of an abstract entity?

@nfactor1995: If I remember correctly the Black Flash is basically Death for the speedsters that use the Speed Force.

A Dark Aspect of the Speed Force, The Black Flash fulfills the role of death to speedsters within the DC Universe, returning them to the Speed Force.

You can read about the character here, since this is a wiki site.

That's what I thought he was asking, at first.