“That which the light does not touch is not mere anathema. It is poison.”
The Stellar Empire is a massive multi-cluster-spanning empire, built around the Stellar Faith (Sometimes referred to Arcturanism). The faith is built around the words of the Starborn Arcturus, who uplifted the peoples within the Empire, in the days before the Rapture.
Followers of the Stellar Faith believe wholly that Arcturus abandoned them for their failure to adhere to his commandments, and that only penance, and adherence to those commandments will have any chance at atonement, and their possible return.
All humans born are equal. To favor any is sin.
Ability is the blessing of the Starborn. To deny it is sin.
Suffer no thinking machine. To build it is sin.
Remain human. To diverge is sin.
Immortals may beget no progeny.
Arcturus is the light, the sun, the benefactor, the indelible; none may stand higher.
The Empire is organized into a series of Castes, ostensibly established by Arcturus, but whose initial intent has, according to some heresies, been lost to the untold centuries since the Rapture.
The best known of these are the three “high” Castes, the Void, the Sun, and the Song. Closest to the Light, blessed by Arcturus with knowledge and power enough to contain and command the lesser Castes. They do so with strict discipline and a firm hand. Inhabited near exclusively by Immortals
Caste Void, commonly called Voidknights, are the Knights of the Black, who are anointed with Flame from the Caste Sun and empowered by the Truth through the Caste Song. They are the burning blade of the most holy Starborn, that which cleaves the Divergent, the Denier, the Builder, the Nepotist.
Caste Sun, commonly called Sunforgers, are the Shapers of the Flame, who can shape weapons carrying the power of the Starborn through arcane and occult ritual and secretive mechanism. They are the architects of great works, the shapers of worlds, the bringers of plenty and beauty and function.
Catse Song, commonly called Truthsingers, are the Sirens of the Word, who sing the Truth of the Starborn, and empower that which is of the Flame. Without the Song, the Truth, there is no Flame.
Below these three are the petty Castes, those which build the mundane machines of everyday life, the subordinate common soldiers, the artisans who labor under intense scrutiny, the clerks and thinking servants, the governers and dukes of planets and systems, the ones who raise and outfit the Leviathans, among many others. Alone, their voice is nothing, a weak cry to a choir of Stellar power. The higher Castes would prefer it remained that way.
Even below this are the new born, the serf, the wastrel, the casteless, the labor and the sweat and the blood and the crying mouths of the mass of humanity. All are born equal. Most stay there.