The Navigator Houses8 Houses led by the Emperor Above Heaven, the highest in a long hierarchy of nobility. The Navigator Houses are the largest nation, and the only one with manufacturing capability. However, their industry has weakened since The Retreat, when Keter's Disciples forced them out of the Secondary Habitation Ring.
The nobles of the Houses have complete power: they can take whatever they want from anyone. Taxes are whatever the person above you says you are, and they don't always stop with money. Falling into debt with the nobility can get you killed. Or worse.
Food is scarce - the Navigator Houses have to force food to grow on the metal walls of the arkship. They get most of their food and water from the Coolant Sea; a long, dangerous journey, not helped by the Sea's inhabitants.
Ghoul NestsGhouls are failed clones, created when one of Keter's biotech labs malfunctions. When they're found, the Disciples throw them out into the ship, and leave them to die. Ghouls have no industry - their technology ends with spears and blades. They live off stolen food and vermin.
Some Nests are led by a Hanged King, a failed Seraph. While they lack the augmentations of their siblings, Hanged Kings still bear all the genetic modifications of a true Seraph.
Tear-Eater CultsUnited under their Voiceless Prophet, the Tear-Eater Cults slowly chip away at the borders of the Navigator Houses. Without industry, they have turned to nature: Tear-Eater Cultists drink ancient coolant or cultivate growths of fungus in wounds.
They fight quickly - hoping to kill their enemy before their drugs poison them.
The Voiceless Prophet has never been seen. Some say they are a noble in the Navigator Houses, using the Cults to pressure his enemies. Others say the Prophet has been consumed entirely by parasites, and sits alone, slowly dying. The Prophet could even be Keter Himself, editing the genetic code of the fungi the Cults grow to send them specific hallucinations.
The Ayir Fortress-Clans
Long ago, the Ayir lived on their own, far from others. Now, many of them live in tall, stumbling fortress, marching eternally across the world. None of them will say why they left their ancient cities. None of them ever speak of their history.
Each fortress is inhabited by several Ayir families, each with dozens of members.
The Fortress-Clans are very secretive - visitors are never allowed into their walking cities. Trade is handled on the outside, by heavily-armed groups backed up by the formidable armaments of the fortress.
The People of the Sea
The Coolant Sea is all that remains of the massive hydroponics bays Ein Soph once had. Over time, the decks corroded and collapsed, leaving a cavern dozens of stories high, peppered with reinforced pillars and dimly lit by ancient sunlamps.
The People of the Sea creep across the pillars, careful to never go down to the surface of the Sea. Their deafened scouts stay on watch for intruders, while their hidden snipers ready their weapons.
The People of the Sea have been attacked by people seeking their food supply for decades, and every year their defenses get more complex and their citizens get more prepared. In combat, the People stay hidden, sending out small groups to lead invaders into traps. The People are the only civilization to build sniper rifles, allowing them to make the most of their range advantage.