Since the Flash’s main ability is super-speed, there are very few characters in DC Comics who can keep up with him, let alone beat him. But there is one entity that even the characters with access to the Speed Force cannot outrun: The fearsome being known as Black Flash.
In DC lore, the Black Flash acts as the Grim Reaper of the Speed Force, tasked with reaching out to speedsters in the moments before their deaths and drawing them back into the Force. As a result, several speedsters including Barry Allen, Wally West, and Johnny Quick have had encounters with the Black Flash, and few have lived to tell the tale.
What makes the villain particularly terrifying is that his origins are shrouded in mystery. Some comics theorize that Death of the Endless, the Black Racer, Nekron, and Black Flash are all different personifications of a singular Death. Others hint that Barry Allen turned into Black Flash after his death, and that the current Black Flash is a time-displaced version of him. What is clear is that he’s terrifying, implacable, and enormously powerful.