Understanding "Notes by a Certain Noble Individual" and Snezhnaya's World Quests
(Spoilers for 7.0 World Quests and Optional Readable Content of course)
I finished all major WQs a bit ago and I've been reading up on the information and notes contained in the areas bit by bit. I am decently aware of most of Genshin's lore, but if I understood correctly these notes and the final quest specifically fill in a lot of gaps regarding previously established stuff which I do want to ask for clarification here since I'm honestly not that sure if I understood some things right.
1. Fate, the Abyss, and the purpose of the Shadow Realm.
If I understood the notes correctly, the Shadow Realm is the "antithesis" to both Fate and the Abyss, which was created by The Voyager, Anarcharsis. The notes describe "possibility" as a pure white light and the anchoring of fate as the dividing of that light, which in turns causes the abyss as the resentment of the unreached paths. The Shadow Realm though teams with possibility, as all possibilities there are engaged with as seen in the final battle against the body of the Belyi Tsar, where all possibilities of Prime Ice constructs are used by the Eye of Graeae to make a path for the Traveler.
Phanes anchoring "fate" to a singular route along with creating the Firmament creates a world where the Abyss cannot be made within it, but it festers and builds up outside of it. The Shadow Realm then acts as a "buffer", if the Abyss (the resentment of unmet possibilities) enters the Shadow Realm (a realm that engages with all possibilities) it wouldn't be able to take root inside of the Human Realm (a realm ruled by Fate) as it would've been dispersed by the Shadow Realm. Which is why the notes describe it as a "film of oil" that separates the Abyss from Teyvat.
Additionally, after Anarcharsis and Koitar's rebellion failed and Hyperborea was struck by a Celestial Nail, the ruins fell into the Shadow Realm.
2. The Third Descender and their relation to the Belyi Tsar.
Hymns of the Far North from Nod-Krai says that the Third Descender (Saarelainen) opened up the gates to Pohjola to court the daughter of Pakkaisukko, he opened the gates knowing it would incur the wrath of Phanes, and was then turned into the 7 Gnoses. Now I originally thought the northern half of Nod-Krai was Pohjola according to some datamines, but that seems to not be the case now as revealed by the Belyi Tsar's notes.
The notes heavily imply that the Saarelainen was killed for opening the gates to the Shadow Realm. (which I am slightly confused about since historically Phanes only strikes at the abyss/those who attempt to usurp them but opening the gates to a realm created by Anarcharsis might be seen as an attempt to usurp him idk) Now combining the information it seems that Saarelainen opened the gates to the Shadow Realm for the Belyi Tsar to court his daughter, which based on the WQ should be Aksinya(?)
Yes, I know that Aksinya loved the Belyi Tsar and this is somewhat wacky; but if I understood correctly, the Tsar found and adopted Aksinya from the ruins of Hyperborea and brought her in as Court Jester despite public discrimination against humans in the past. This was to give her both the autonomy to move around the castle, and to also complete Hyperborea's Primordial Human Project. Now I don't know if this is a case of inaccurate records on the Frostmoon Scion's part or Irminsul shenanigens, but considering they've recorded most information correctly I'd assume it's either another daughter of the Belyi Tsar that wasn't mentioned or just a figure of speech.
3. The Primordial Human Project and a TL;DR of the 7.0 WQ Series.
If I got it right, the Primordial Human Project was an experiment by the Hyperboreans to create an entity to replace Nibelung's role on Teyvat, using the remains of the Cryo Sovereign; But wasn't completed due to Hyperborea's fall. However, the experiment birthed the Belyi Tsar ~1,000 years after Anarcharsis and Koitar's rebellion. If I understand it right, the Eye of Graeae was the second attempt at the project, this time run by Aksinya, utilizing the Eye of Graeae to house the consciousness of the Proto-Man. (which I will call Goggles because typing the full name out is annoying)
Goggles fell in love with Aksinya, the adopted daughter of the Belyi Tsar. However, realizing that completing the Primordial Human Project would become a threat to all life, he asked Koshchei, Pavlina, and Alvis to divide him into three pieces and to throw Aksinya into the Shadow Realm to prevent the project's completion. Until the Traveler found Goggles and across the quest helped him regain his memories. In the end, Goggles merged with the body of the Belyi Tsar and became the Primordial Human and was subsequently stopped by the Traveler ending in both him and Aksinya falling together endlessly in the Shadow Realm.
This is generally the information I fully understood from the WQ and world notes, information regarding Dr. Koshchei's hivemind, Pavlina's marriage ceremony, and Alvis's... anecdotes aren't really relevant past individual character goals, but I generally understood it. If I missed anything or misunderstood some things feel free to correct me!