Christ was a man, the White God left part of himself open to infection, and why else have such articles used in a ritual?
The fact that the nails were angels themselves, makes me think this, I thought originally that the nails and the swords had been created by the ritual and that was it’s purpose, but the nails were already powered up, so what was the purpose?
Given the White God is an intellectus the infection and cure may have been deliberate to get information on Nemesis and the Outsiders, and figure out a cure I doubt any intellectus includes knowledge of what is happening beyond the outer gates. If Lucifer were patient zero for Nemesis then the object is to eventually cure him. Archangels are ON their guard NOW and can’t be Nemfected, but if Lucifer let Nemesis IN that is a different matter.
This may be what Nicky was after in the heist, why he has concerns about the Black Council and Nemesis. The Fall may have been perpetuated by a Nemfected Archangel, other Fallen believed Lucifer in the same way people believed Maeve. This could be Anduriels redemption arc.