What is Ultima, the High Seraph? Where did she come from?
A pretty big revelation we learned during the Pandaemonium: Anabaseios story was that the Heart of Sabik was Black Auracite that was discovered by and experimented upon by Athena.
And it has been very heavily implied by the story that the origin of auracite overall is Ultima, the High Seraph. The only exception to this, at least as far as I know, is how Moenbryda was able to somehow reverse engineer auracite into what we know as White Auracite, which we have used to contain, and subsequently destroy, multiple Ascians.
The lore implications are that Ultima, the High Seraph arrived on Eitherys long before we, the player, set foot onto Elpis and that, while she is not directly responsible for The Final Days, she and her auracite have created myriad problems not just on The Source, but on The Thirteenth as well, which implies that Ultima, the High Seraph, was also sundered, which is likely how we were able to defeat her in the Orbonne Monastery alliance raid.
What is Ultima, the High Seraph and where did she come from? Is she a "Calamity from the Skies" not unlike Lavos or Jenova and, perhaps, her origin point is completely untraceable? If so, are there other Ultimas, the High Seraph out there? Could we see other similar Ivalician Espers come of this, such as Zalera the Death Seraph or others that may have only been conjured in the Ivalice raids as memories of Ultima?
I have too, too many questions, so please refer to the title of this post for a more concise question. Thank you so much!
Did Louisoix have any children besides Fourchenault?
In the Lodestone short story "In Louisoix's Wake," Fourchenault is mentioned to be 'Louisoix’s eldest son,' which implies that the existence of at least one younger brother. But come Endwalker, there's nothing to indicate that Fourchenault has any biological siblings. Would any 'adopted waifs and rescued orphans' that Louisoix brought to Sharlayan like Thancred be counted as one of his children?