Motion Blur: A key plot-point where security footage at a high school was found to show a strange blur. Using experimental technology to colorize it, the agents reveal the blur is made up of the school colors, suggesting that it comes from the jacket of one of the (superpowered) students.
One-Hit Polykill: A teen essentially commits murder-suicide in this way, shooting someone in the back, and then using her super speed to step into the path of the bullet as is passes through.
Required Secondary Powers: Averted. Using super speed places stresses on the human body that it isn't designed to handle, resulting in appropriate medical issues (exhaustion, muscular and skeletal damage, etc.).