Complex sentence: To conserve energy, they combine their essence in just six Taelons who go down to the regeneration chamber, just as the remainder of Vorjack's Jaridian fleet arrives on the scene.
Split into simpler sentences: To conserve energy, they combine their essence into just six Taelons who go down to the regeneration chamber. At the same time, the remainder of Vorjack's Jaridian fleet arrives on the scene.