Since the speedforce is the source of kinetic energy in the DC multiverse, and Barry is the Speedforce. Wally is faster than the very concept of motion itself.Wally takes the staff Tempus gave him to get rid of dark matter and attempts to blast what's consuming the planet, but it doesn't work. The Incursion Point itself is made of dark matter. The Flash responds by pushing himself "faster than light and thought" and faster than anyone before him, which is entirely in the realm of a speedster's abilities. However, Wally then starts going "faster than the Speed Force."
Barry can