To put it quickly, Aurash and her sisters Sathona and Xi Ro were the last children of the proto-Hive Osmium King, who had a dead Worm that spoke to him of dangers to their world When the King was killed they took his dead Worm and eventually found living Worms in Fundaments core. Upon forming a symbiosis with the Worms, Aurash took on the King morph like her father before her and changed to the male Auryx, the King of the Hive and the First Navigator. His sisters became Savathûn, the Wizard, and Xivu Arath, the Knight who oddly seems to still be female even though Knights are supposed to be male Later on, the Hive were almost destroyed and Auryx had to kill his sisters to gain their strength, which he then used to kill Akka the Worm so he could speak with the Darkness. The Darkness taught him how to Take, and he emerged as Oryx, the Taken King. Oryx then went on killing everything in his path and in doing so found ways to revive his sisters. For the full version of the Hive's story (basically summarizing the Book of Sorrows), click here: https://www.bungie.net/en/Forum/Post/225707058/0/0 But I heavily suggest continuing your reading of the actual Book of Sorrows Good work with the post btw, I just wanted to get specific on the transformations