What is meant by "Empire's Twin Heroes"

Two vast fleets faced off three astronomical units apart. The spacetime disturbances caused by their mass warp-ins had yet to subside, and the layers of distorted ship silhouettes formed a spectacle of breathtaking grandeur.

Vice Admiral Pulaier's flagship, Flashpoint, stood at the center, with forty-three Minotaur-class battlecruisers unfolding in an inverted V-shaped wedge formation along either side. Frigates and fighters darted between the warships, and from afar, the exhaust trails of tens of thousands of thrusters resembled an immense swarm of comets.

The massive fleet opposite them was equally intimidating. Eighty carriers and one hundred and twenty Void Rays surrounded magnificent motherships and Arbiters at its center. More Scouts, Phoenix fighters, and Warp Prisms emerged in layer upon layer from beneath rippling cloaking fields, while enormous carrier-based fighter swarms poured from their hangars like enraged bees.

Though it was merely an advance fleet, its firepower already rivaled that of the Empire's main fleet.

This was the greatest fleet in Protoss history. None could withstand the full force of the Firstborn's wrath. Wherever the Golden Armada went, it was invincible.

The Golden Armada bore all the Firstborn's hopes of reclaiming the glory that belonged to the Protoss, seeking only not to disgrace the honor of their fallen forebears. But things had ultimately gone against their wishes. Corrupted by Amon, the Golden Armada had now been given only one mission: to cleanse everything with flame.

The Golden Armada now resembled a slug winding its way through the Milky Way Galaxy, leaving behind countless dead planets reduced to scorched wastelands. This fleet was so powerful that it did not even need to worry about its flanks or rear.

Pulaier knew there was no longer any possibility of negotiation or communication with the Golden Armada's Protoss commanders. Every human hail vanished without a trace,