Oryx
Oryx began as Aurash, a female Krill princess who dove to Fundament's core, took a Worm-larva, and changed sex in the morphing. He earned the power to Take — to seize a being and rewrite its will into a Darkness-slave — only by murdering his own Worm God, Akka, and inscribing the secret on the Tablets of Ruin.
Why he mattersThe Books of Sorrow are his autobiography — and a trap. He wrote them so whoever kills him inherits the Sword Logic. Slaying him in King's Fall arguably proves his philosophy. See the Hive history and the Sword Logic.