What I recall specifically about the perceived need for an Incarnation of the Radiant Lord in Nave (for which role St. Lucian / Lucius was chosen) is that (along with sacrifice on a divine level being a supernally noble and beautiful idea, with all kinds of plot complications and character to be revealed in parables) there was a kind of gap left from the lore of Agon, a world wherein all humans might have been and all Mercians were certain they were *descendants* of Auros, not just His Creations.
Emotionally, it was felt, it would be almost as rewarding to be able to get into a character who could say "my God was born among us and died for me!" as it would be to assume the persona of one who could say "I am of the blood of Auros". For those who do get into character at all, that is. Those who don't were assumed not to care.
St. Lucian (note spelling) was around in, I believe, 2010, if you are trying to determine a timeline.
Comic Relief:
Spoiler:
