The echo will mostly likely be the hive or krill(before they became the hive) and nokris will probably play some sort of role in the story do to him committing heresy/blasphemy to the sword logic and was disowned by oryx and almost wiped from history except for one statue. But what the echo can do is up to anyone guess but maybe it will control the taken since maya echo controlled the vex and fikrul a controlled the scorn and can create worlds

First and foremost the title of the coming Episode, Heresy, is quite telling. For the Hive, the single character that has been labeled a [b]heretic[/b] is Nokris for his research into and practice of using Necromancy to revive dead Hive. Under the Sword Logic the individual bears the immediate responsibility for their continued existence; they continue to live because they earn the right, or they are destroyed through their own weakness. The act of dying itself is proof that one does not deserve to live. There is some wiggle room in this due to the existence of Throne Rooms, extra-planar spaces in which tremendously powerful being can rewrite the rules of the Universe in their favor, effectively cheating death. Among the Hive, this level of power was notably obtained by Oryx, Savathun, Xivu Arath and Crota. So intent were these Hive Gods on obtaining greater power for themselves and their race that, in their own perverse way, killing each other to gain power and prove the power of those who were able to brings [i]themselves[/i] back from death became a sign of familial love. We also know that after the defeat of Savathun during the events of Witch Queen, a faction of the Lucent Brood led by the wizard Šimmumah ur-Nokru traveled to Titan in an attempt to resurrect Oryx using the Necromantic arts gleaned from Nokris. - During the ending cutscene that plays upon completing the Excision mission there are a series of still images that hint toward the three Episodes for the year that followed: [b]Echoes[/b] - a number of Vex approaching Failsafe at her station on Nessus. [b]Revenant[/b] - Mithrax gazing into the distance while Eido reaches out to him, followed by a shot depicting Spider, Fikrul, Eramis and Variks. [b]Heresy[/b] - Savathun grasps at Oryx’s Sword, Willbreaker while her wings close in around her. Willbreaker remains where our Guardian left it at the end of the Taken King expansion, aboard the Dreadnaught, in orbit around Saturn and relatively close to Titan where Oryx’s body ultimately settled after he was slain. Ultimately Savathun was freed from the call of her Worm which she had to constantly feed Imbaru, a power she derived from the propagation of lies and false beliefs. If Savathun rejects the dogma of Sword Logic and commits Heresy (in terms of the Sword Logic anyways) by resurrecting Oryx in order find a way to free him from the demands of his Worm, this may be a way to express a form of familial love with which she has had little direct experience. It [i]may[/i] be that the Echo tied to this Episode will have the power to free the Hive from the demands of their individual worms without the necessity of becoming Hive Guardians, a means of granting them freedom to choose to do as they wish. Also worth considering is the possibility that, with Oryx having been the Taken King before his death, this Echo may instead (or even [i]also[/i]) present a way to reverse the effects on individuals who have been Taken, providing the prospect of freedom to a great many. There’s nothing in the lore that says an Echo [b]has to[/b] initially be controlled by a direct Antagonist bent on using it to exert control over others; the third Episode [i]may[/i] revolve around us helping Savathun to find the proper way to wield it to achieve her aims (which just so happen to redound to our benefit as well), all the while perhaps fighting off Xivu Arrath’s forces as she tries to steal the power of the Echo for herself. - [i][u]As an addendum:[/u] If the above proves prescient and Savathun’s intent is indeed to free Oryx of the influence of his Worm, that doesn’t necessarily mean she will ultimately be [b]successful[/b] in the endeavor. It [b]might[/b] better serve the narrative if Savathun resurrects Oryx but he rejects her salvation (avoiding a “we redeemed Oryx” scenario), choosing instead to retake control of the Taken while continuing to feed his Worm. There has been some (not entirely unjustified) speculation within the lore community over the past year or two that, unlike Calus and Rhulk who were disciples of [b]the Witness[/b], that Oryx may instead have been in contact with and gained the power to Take directly from [b]the Winnower[/b]. Oryx, still believing whole-heartedly in the Sword Logic, may not care about the revelations Savathun learned at the end of Witch Queen and decide that the Witness only died in their failed pursuit of the Final Shape due to their fundamental weakness, and that Oryx will pursue a quite different vision of the Final Shape as a direct scion to the Winnower.[/i] (΄◉◞౪◟◉｀)