Phoenix

The first war has taught the Protoss that they did not have sufficient weaponry to deal with the enormous magnitude of the swarm. The redesigned Corsair, renamed the Phoenix, was created specifically to reduce swarms of lesser creatures into rubble.

Strategic Properties
Although the Phoenix possesses a weak ground attack for harassment, their primary purpose is aerial superiority, and are designed to counter enemy fighter class ships. Their overload ability allows the Phoenix to attack all air units nearby, making them utterly deadly against swarms of small vessels. The attack, however, will barely scratch the armor of capital vessels.When grouped with Warp Rays, the two ships complement each other's weaknesses are become a formidable fleet.

When using the Overload ability, a Protoss player should take care and not overload all his vessel in one go. This allows the opponent to retreat his vessels and return when the Phoenixes are recharging. An experienced player will rotate his overload ability, so that the fleet is never defenseless