Speaking of Phanes, Neuvillette says they had to create the gnoses with the Second Who Came because Phanes was deeply wounded in the fight and couldn't control the law of the world normally. IMO this likely means Phanes must have also been corrupted by the abyss.
>Severely wounded in the great war of vengeance, the usurper had their functions ruined, and could no longer use their absolute authority to suppress the original order of this world. To continue to subdue and control the resentments and loathing of the world, the usurper and one who came after created the Gnoses together. So it came to be that an order was made to be upheld, and thus did humans come to only possess these seven remembrances, and all fragments of the primordial were driven to devour each other.
But the gnoses were made from the Third Descender's corpse and thus are cursed objects like Skirk said. Either way, the Archon War was orchestrated by Phanes and the second who came to maintain the status quo.

This whole thingg prorbably has to do why the Tsaritsa wants to gather the gnoses to begin with.