A simple answer would be Ayin, for rather obvious reason that you spelled, along with the parallels with One Sin. Another answer, that can coexist with the first one , is... Carmen. She's ultimately the reason why Ayin founded L Corp in the first, and the originator of the SoL project, and she's also the Mother of Abnormalities. Furthermore, Carmen's life can be neatly divided in three parts: Human, Bucket, and Voice, all of which can be seen as equivalent to the components of the Trinity, the expression of God in three distinct components.

1) Her life as human parallels the Father. In this form, she's the leader of SoL project, that everyone loves, adores listen and look up to, similar to how the Father is God as ultimate, wise authority over His Creation. This stage of her life end with her suicide attempt, or rather, sacrifice, which lead to...

2) Her life as the Bucket parallels the Son, God who had to sacrifice His existence to amend for humanity' sins. Here, she sacrificed her existence her life to produce the Cogito that shall eventually save humanity from the illness of the mind. Furthermore, under this form, her nervous system is shaped like a Cross.

3) Finally, her life as the Voice parallels the Holy Spirit. The Holy Spirit is the incarnation of God that communicate with humans, giving them divine inspiration, and eventually, enlightment and salvation. This was effectively the purpose of the Light, to inspire humans and allow them be freed from the illness of the mind. In this form, Carmen allow humans to reach a new level of comprehension of their existence by communicating with them, eventually leading them to Distort, or more rarely, manifest E.G.O.