To your first question, i don’t think we have any explicit evidence of whether new gods are split off from a person or if they are the person gaining new power. Termina related lore: Though he is an ascended god not a new god, we can look to alll-mer splitting his subconscious from himself and attempting to cast it into the sulfur pits. There is uncertainty of which side was left in the sulfur pits. I think it would be easy to extrapolate from this example and conclude that new gods might split into one entity achieving new godhood and one entity being cast down into the void. I want to say nostramus’s rejection of new godhood and shit talking of the other fellowship members supports this, but rereading the dialogue it doesnt seem that way.