It seems they used Gnostic texts, in this case the apocryphal Gospel of Judas' reference to a being called Saklas.

A somewhat agnostic approach to a gnostic "reality" in the games. Gnostian Christ can be found rendered from the Apocrypha known as: Epistle Apostolorum, Mary Gospel, Book of Enoch, and Gospel of Thomas. Various other examples fall into possibility, but these 4 form this separate ideological foundation.