For the next hundred years, Oryx fought the combined forces of the Ecumene. Where as before he and his Hive were unable to stand against these “lords of matter and physical law,” Oryx was now able to turn the Ecumene’s own units against them. We’ve seen some pretty devious Taken enemies as Guardians, and that’s with Oryx just subverting Fallen, Hive, Vex, and Cabal. I like to imagine that a Taken Ecumene War Angel must have been a beautifully terrifying sight!

After a century of pushing back the Ecumene, Oryx’s forces overran the Ecumene Council located on something called a Fractal Wreath. We don’t know exactly what this was, but I like to imagine the Ecumen’s center of government was located on some sorts of awe inspiring megastructure hanging in space that only an empire that had bent math and physics to its whim could even hope to build. Maybe this Fractal Wreath could have looked like a cross between a Halo and one of these:

As Oryx finally reached and destroyed the Ecumene Council he also did something just as impressive and frightening: He somehow brought Xivu Arath back to life even though he had killed her in his Throne World! She arose from the destruction of the Ecumene saying to Oryx: “I am war, and you have conjured me back with war.”

For the next forty years, Oryx and Xivu Arath continued their battle against the Ecumene until they neared the Dakaua Nest. Remember, it was the Dakaua Ministry of War that first tried to rally the client races of the Ecumene against the Hive. And it was the Dakaua whose mercenary explorers discovered and revived Taox from her long twenty thousand year stasis. Wiping out the Ecumene council may have been a major victory, but if the Dakaua were the lead race of the Ecumene, nearing their Nest may have been an even more significant event. Its likely that the Dakaua knew this and put up one heck of a fight!

Maybe the Hive’s conquest of the Dakaua Nest was proceeding too slowly for Oryx’s liking or maybe he was just feeling devious one day, but for some reason Oryx contacted the Dakaua and asked for their support in killing his sister. He told the Dakaua he had become jealous of her. Oddly enough, the Dakaua agreed to help him!

It sounds a bit silly, but we have to conclude that Oryx request appeared genuine. It must have been more than him just sending a quick text message. We aren’t told exactly how he convinced the Dakaua to agree to help him, just that they were desperate enough to do so. Maybe he offered them a cease fire and actually ordered his forces to stop their advance? Or maybe he turned them away from attacking the Ecumene forces and instead had them attack his sister’s forces?

Whatever Oryx did to earn the trust of the Dakaua was apparently convincing enough that he and Xivu Arath were able to lure them into so cunning and deadly that soon the entire Dakaua race was erased from the galaxy! And again, something just as shocking happened: With the destruction of the Dakaua, Oryx was somehow able to bring his middle sister Savathûn back to life! “I am trickery, and you have conjured me back with trickery,” she told her brother. But she too had been killed in Oryx’s Throne World, so how is it possible she could be brought back? Shouldn’t both she and Xivu Arath be dead?

The best explanation I can come up with is this:

When Oryx was first killed by his sister during the war against the Ammonites the worm gods told him: “From this day forward, Auryx, you and your sisters will each survive death – so long as you aren’t killed in your own throne.”

Look carefully at the beginning of XXVI: star by star by star, the book where Auryx killed his sisters to gain Akka’s power to speak directly to the Deep. It specifically says: “Beneath a gree fire sky, in the throne-world of King Auryx, or lords embrace.” See that? Savathûn and Xivu Arath were not in their own throne, they were in their brother’s when he killed them.

At some point in the future Xivu Arath will have this to say about her death at the hands of her brother:

Once, I permitted Oryx to kill me so that he could gain the sword logic and overcome Akka our God. This left me trapped deep in my throne. But Oryx my brother made war upon the Ecumene and in that war he described me, for I too am war. Thus I was resurrected.

Many many hundreds or thousands of years later Ikora Rey will have this to say about Crota:

...is his world the apex of Hive power, or is it the youngest and most accessible of a string of netherworlds, each host to a more terrible Hive archentity?

So maybe killing an Ascendant Hive in the Ascendant Plane is not enough? Maybe they have to be killed in their specific throne world? Is this how Akka can be still alive even though Oryx killed it? Maybe it too was outside of its own throne-world? We killed both Crota and Oryx within their throne-worlds, but what about the War Priest, or Golgorth, or Oryx's twin daughters?

In the end, what was left of the client races of the Ecumene knew the reappearance of Xivu Arath and Savathûn, along with the extinction of the Dakaua, was so unbelievably bad that they each fled into hiding only to be hunted down by Oryx and his sisters over the next thousand years. We’re told that the Hive exterminate the races of the Ecumene so completely that the only record of them at all is the Books of Sorrow… and curiously, within the mind of Taox.

Wait... Taox escaped again?!

Sources:
XXIX: Carved in Ruin
Crota, Son of Oryx
XXXV: This Love Is War

Previous: 14: Oryx - The Taken King
Next: 16: Oryx’s Pyramid Scheme