Fog Realm was one of the Realms created by the Accelerons. It is a realm that is filled with fog that blocks the driver's view of gigantic obstacles and treacherous switchbacks, and causes collisions as well.
It was one of 3 Racing Realm that the Racing Drones won prior to Ignition.
The Fog Realm AcceleCharger (Fog Vision) will allow the driver to see clearly in the fog.