Void Chasers are the Stealth Units for the Wardens. They are the only Stealth Units that can switch between normal and stealth modes. With that ability, why is it still rated the worse Stealth Unit of all? Because in stealth mode, they are only good for spying on the enemy base and unlike other Stealth Unit, they can only attack in normal mode and will act like Worker Units while in stealth mode, so the Void Chaser can be the only weak point of the Wardens, besides the requirement of alot of carefullness. They use electrical whips to attack. Don't try to send 1 or 2 Void Chaser(s), let them turn invisible, visible again to attack and then try to turn them back to invisible, cos by the time the warp button is fully recharged, all the Void Chasers will be wiped out, so if you want to perform this, do this with 3 or more Void Chasers.
However, Void Chasers are second-tier infantry and can be sent onto the field faster than other stealth units, making them viable early scouts. Rushing Void Chasers before the opponent has invested in detector units is possible.