I finished Act 3 Week 1 and Oryx has interesting words to say about himself and his actions during the Ecumene War. He talks about and confirms that killing Xivu Arath and Savathun in his Throne World was a true death. He mantled their powers to kill Akka and become the Taken King. Then he calls his other self - the one who lived - "betrayer Taken King" for giving Xivu Arath and Savathun their lives back and believes this act "poisoned" the Hive's Sword Logic, and blames this act for what Xivu Arath and Savathun have become now. This is interesting because I had assumed from the "Books of Sorrow" that resurrecting Xivu Arath and Savathun in the manner he did was always in the plan. He kills Akka to gain the secrets of the Deep, and over time when he is powerful enough he conjures his siblings back through great acts that embody them - cunning and war, respectively. But for this Oryx, a memory taken from when he was fresh off killing Akka and claiming the power of the Taken, that seems to not be the case. There are two possibilities: one is that it was the plan from the start, but the Echo seeing Savathun and Xivu Arath at present has concluded such an act was a mistake, a betrayal of the Sword Logic. The other is that it was never in the plan, which means something changed in Oryx during the Ecumene War. My simplest guesses are time and love for his siblings. In [url=https://www.ishtar-collective.net/cards/xxix-carved-in-ruin#books-of-sorrow]Carved in Ruin[/url], Oryx waged war with the Ecumene for a hundred years before he conjured back Xivu Arath, and another fifty before conjuring back Savathun. In both cases, Oryx is glad because he loves his siblings. Then there is Crota, his son. While Crota was a vital contributor to Oryx's tithes, Oryx stormed Sol as soon as he was able after his death. The Echo also questioned his other self's motives here, calling it a waste of his logic because "the dead deserve extinction". Between these two events, I think we can see how Oryx changed after he became the Taken King. He was still devoted to the Sword Logic, to the point he disowned Nokris for practicing necromancy, and erased the memory of him from everything save a single statue in the Dreadnaught. However, he loved his siblings, and he loved his son, too much to follow the Sword Logic to the letter. It fits the theme of Heresy rather well. Both Savathun and Xivu Arath are driven by their love of their brother, even if the Echo is the memory of a younger Oryx given form, not the brother who is long dead. Xivu Arath wants him back so they can continue on their path of conquest; Savathun wants to free Oryx from the path of the Sword Logic, which is why she reveals the truth to him in Act 2.