Faction Paradox (in-universe series)

A series of books of speculative fiction existed in the parallel universes making up the 10,000 Dawns, including in Graelyn Scythes home universe. They added up to "one great narrative of a war of powerful beings and the humans that interact with it". This war, in another universe beyond the Dawns, was a reality (PROSE: Rachel Survived) as the War in Heaven. (PROSE: The Book of the War, etc.)

Contents
Published as paperbacks by a number of publishers including Obverse Books, the series included The Book of the War, Burning with Optimism's Flame, and Head of State. The latter concerned itself with the story of Rachel Edwards and her investigation of mysterious murders surrounding (PROSE: Rachel Survived) Lola Denison's presidential campaign. (PROSE: Head of State) Written by Andrew Hickey, it contained word-for-word extracts from Rachel's blog, but also other material whose relationship to the present-day narrative was more ambiguous. (PROSE: Rachel Survived)

History
In Graelyn Scythes's home universe, Head of State was published in the early 21st century. There existed a real version of Rachel Edwards in this universe; she found out about the book's coincidental existence, but the events therein bore no relation to her life, and she "just laughed it off". The book endured through the subsequent centuries, and in 2471, it was read by a young Graelyn Scythes, who was still living in Moscow and had yet to break free of her abusive mother's influence. Rachel's steadiness, and her comfort with her own bisexuality, were inspirations which helped the young Graelyn keep going despite her circumstances as she figured out her identity and place in the world.

At some point, a cache of the books, together with the Book of Books, ended up in the Totality in the 18th century. The books were discovered in the 21st century and transferred to the New York Public Library, where they were set to be unveiled with much pomp, with journalist Rachel Edwards covering the story and interviewing Johannes Englesberg III, a scholar who had not realised the true nature of the Book of Books, being more interested in the other texts and describing the Book as an unimportant "outlier" which "appear[ed] to feature many texts condensed within it" with no clear narrative connection to the rest.

Other parties, however, were much more interested in the Book of Books than in the other texts. They included War powers such as people in robes, people with masks and people in "silver jumpsuits", but also powers from the 10,000 Dawns. The Arbiter of Knives was the first to tell the Arbiter of Eternity about the Book, thinking it would be a way for them both to while away eternity, with the incredibly old Arbiter of Eternity having finished reading through all the books which had ever been published in the 10,000 Dawns. She was overheard by spies from the Great Assimilation and the Dawn organisation, who followed her to the Totality to get to the Book first — in Dawn's case to prevent anyone from stealing it at all, as they feared the consequences if the Firmament-equivalents learned of their trepassing into the Totality.

Arriving on Earth, the interdimensional spies also caught the attention of the Strid, a local alien species who decided to get the Book before anyone and then auction it off to some of the interdimensional parties, desiring a planet of their own where they'd rule themselves and be guaranteed a supply of bodies. After the Arbiter of Knives cut her way through the representatives of the local power, this auction began to take place, with the Firmament and Assimilation each offering the Strid a planet while Dawn refused to negotiate with the murderous beings and simply gave them a flat ultimatum to surrender the book peacefully. In the end, however, Rachel Edwards, whose temporal shadow the visitors were using to cloak their presence, took advantage of this position to win back the book herself, threatening (as a pure bluff) to kill herself and thereby expose them unless the Strid gave her the book. Accepting they'd been beaten, the Strid, Assimilation and Firmament representatives all retreated.

Because they had been tainted by Strid biomass, the books were taken away from the Library to a secure location; the official story was that it had been found to be infected with a long-dormant parasitic fungus, on which the deaths caused by the Arbiter and Strid were blamed. (PROSE: Rachel Survived)

Behind the scenes
Although never named in Rachel Survived, the books are evidently in-universe versions of the real-life Faction Paradox book series.