Negative Flash is a term used for speedsters whose powers come from the Negative Speed Force.
The original Negative Flash was Barry Allen, who gained a connection to the Negative Speed Force after being trapped in the Negative Speed Force for a time by his arch-enemy the Reverse-Flash. Meena Dhawan succeeded him after stealing Barry's powers from him.[1]
The concept of Negative Flash was created by Joshua Williamson, Paul Pelletier and Howard Porter, first appearing in The Flash (Volume 5) #27. (2017)
See Also