The First and Final Firmament are the rulers and keepers of the 10,000 Dawns, playing a role equivalent to the Superiors of the Totality. (PROSE: Rachel Survived, White Canvas). The Firmament could live forever by transferring their soul and consciousness into new bodies upon death with the use of Resurrection Tanks. While most of these tanks were housed on the Firmament homeworld, certain renegades had their own tanks in order to stay independent from their homeworld, such as the Knights of Sky (PROSE: Bad Friends, Better Weaponry).
Firmament frequently travel in a ship called a Factory of Crystal, or Foce for short. These moon-sized ships can shrink down to minuscule size, and travel through space, time, and alternate realities.
The Firmament became interested in the universe of the Great Houses because of the Book of Books and sent the Arbiter of Eternity and the Arbiter of Knives to obtain it. (PROSE: Rachel Survived)
The Firmament were turned to fiction by Auteur and later saved from it by Graelyn Scythes. Representatives of the Firmament attended the Christmas Needle Agreement and argued with ambassadors of the Bookkeepers. (PROSE: White Canvas).