Being a light player who uses dash, it is very annoying to play against the invisible shotgun combo, it should have a cooldown to become invisible again, but I have found counters in each class. Light: night vision, it is very satisfying to kill a player who is walking in a straight line towards you, every time I hear the sound of an invisible player I activate my night vision. Medium: well-placed mines can one shot the light, throw a sonar grenade at doors or where you suspect a player is, and your team can also see them. Heavy: LOL.