The Vasari possess technologies that can even outclass the vengeful Advent, but because of their transient state and relatively small starfleet, they prefer to rely on guerrilla tactics, using the element of surprise to preserve their numbers whilst devastating their foes. The Antorak Marauder exemplifies this by blitzing their enemies and whittling away at their defenses from the inside. When an Antorak appears near an enemy planet, it will activate a temporary Phase Stabilizer, allowing the entire fleet to converge on the enemy, even from across the solar system.
Using the Antorak: The Antorak is the Support Capital Ship for the Vasari, and a real beast at that. It can use its abilities to hinder enemies while allowing the fleet to move in and wipe them out. It's most important ability, Stabilize Phase Space, turns the Antorak into a one-way Phase Stabilizer Node, allowing the fleet to Phase Jump to the Antorak's position from across the solar system.
Fighting the Antorak: If an Antorak appears, shoot it down post haste. If it is there all by its lonesome, there's a good chance that it can use Stabilize Phase Space to pull in every ship in the solar system.
TEC Tactics: The Cobalt Light Frigate has an ability(Sabotage Reactor) that prevents ships from using abilities, so this can stop the Antorak from summoning the fleet as long as the frigate's have enough antimatter to keep casting. If you've got an Akkan Battlecruiser in the area, hit it with an Ion Bolt to disable it. If you've got a whole fleet there, SHOW NO MERCY!
Advent Tactics: A combination of Disciple Vessels and a Revelation Battlecruiser or two will prevent the Antorak from using any ability. The Disciple's Steal Antimatter ability can drain antimatter from enemy ships and then channel it to friendly ships that need it. This can not only prevent it from using Stabilize Phase Space, but it can also fuel the Revelation's Reverie ability, which prevents targets from taken any action until the effect wears off or when the target is attacked.
Vasari Tactics: Ravastra Skirmishers will be invaluable against an Antorak, because their Interference ability can increase the antimatter cost and cooldown for abilities. This can prevent the ship from using Stabilize Phase Space for a while. The Kortul's Detonate Antimatter can not only damage the ship's antimatter reserves, but also cause it to take damage over time.