The fullest surviving account of the doctrine comes from the Sethian text called the Apocryphon of John, preserved in three copies among the Nag Hammadi codices and a fourth in a Berlin manuscript. There, Sophia, the lowest of the divine emanations called Aeons, tries to bring forth a thought of her own without her consort's participation, an act the text treats as a transgression against the order of the divine fullness, the Pleroma. What she produces is imperfect and monstrous, a being with the face of a lion and the body of a serpent, whom the text names Yaldabaoth. Ashamed, Sophia hides him away, and Yaldabaoth, ignorant of the higher divine realm from which he ultimately derives, goes on to create a host of lesser powers, the archons, and fashions the material cosmos and the physical body of Adam.
In his ignorance he boasts to his own creations, I am God and there is no other god beside me, a claim the Apocryphon of John presents as a direct, pointed echo of Isaiah 45:5, exposing the Demiurge's self proclaimed supremacy as a mistake rather than a truth. This mythic figure is catalogued in the atlas as Character 266. Scholars including Michael Williams and Karen King have cautioned against treating this Sethian narrative as identical to every other ancient system loosely labelled Gnostic, since Valentinian and other schools framed the Demiurge's ignorance and moral status somewhat differently.