We know nothing about what the Echo is or what it might do, but it’s certainly being used in a more interesting way. If the promotional material we’ve seen is to be believed Fikrul has managed to take control of several Pyramid ships with it. And if the Worm Gods are involved there’s every chance his Scorn may now have their interest in the aftermath of the Witness’s death, perhaps continuing on from Rhulk’s experimentation of the Scorn as alternate hosts for the worm larvae. Would certainly add to the events of Episode 3 if the Worm Gods were shopping around for potential replacements.