Speed Force
After "Infinite Crisis", Bart's connection to the Speed Force is more difficult to control because he now contains the Speed Force and, in essence, is the Speed Force. When he taps into the Speed Force, Bart appears to have electricity crackling around him, and the Speed Force inside him becomes so lethal that he initially wears the Flash suit while running in order to prevent it from killing him. After remembering his experiences on an alternate Earth during a fight with Griffin, he began to gain a measure of control over the Speed Force before it was released from his body just prior to his death.