Question: how did oryx become the taken king?
Answer: He killed Akka so that he may steal its ability to call upon the Deep and created the Tablets of Ruin, which gave him the power to Take. His transformation complete, Auryx was now Oryx, the Taken King. ... Wandering within the Deep, and fearing that he was becoming a nihilist, Oryx eventually decided to sire his own spawn.