The Bretheren of Blood (in their language, I'sa'miukai ra sana), refers to a pair of fraternal twin Zahar — among the first generation to be cast down from the Anarai — born in the Salt Desert, back when the brown grasses grew there, when it was known as the Sa'inu'raiau, the Dead Fields. The brother, Çao'sana, was skilled in transmutation magic, and the sister, Ai'sana, in all things to do with blood.

Bretheren of Blood also refers to the Zahar order founded by the siblings, whose goal was to return the Zahar back to their former glory by means of dark magicks.

The Amalgams

Following the fall of the Anarai, the siblings became obsessed with regaining the divinity they had lost. They devised a hypothesis; that the Zahar were but a tiny fraction of the Anarai, but that enough fractions added together still make a whole. With their combined knowledge of transmutation, blood, and bodies, they began work on Amalgams: combinations of animals, constructed to test if the siblings could form a greater whole from lesser parts. Many of the early experiments lived brief, torturous lives, but through more refined processes the siblings were able to create new life forms, even capable of reproducing. The descendants of some of these early experiments still live in the Salt Desert; notably, the lizard horses ridden by the Mukasa Peoples, and the desert's notorious bone wasps.

The formation of the Bretheren and the Sa'fao'je

It didn't take long for word to spread among hopeful Zahar about the siblings' experiments, and they quickly accumulated a following. At first, only a group of disciples, who became known as the I'sa'mikai ra sana (Children of Blood), but later whole schools and temples across various cities in the Dead Fields. The children, under the guidance of the siblings, accelerated the Amalgam research.

The most devout among the children volunteered themselves to be fused into higher forms of Amalgams. These entities, known as Sa'fao'je (singular, Fao'je, literally "joined family"), finally gave the siblings a positive sign, as they were reliably more powerful than their individual parts. Unfortunately, the fusing of minds would always result in a loss of mind, meaning that the Sa'fao'je were mindless, thrashing, dangerous creatures.

The Amalgam War

The creation of Zahar Amalgams began to unsettle those Plains-dwelling Zahar not a part of the Bretheren. By this point, nearly a third of the Dead Fields swore fealty to the Bretheren, and thus could not be taken down in one swift blow. The opposing Zahar chose war.

It was during this war that the most complex and fearsome Sa'fao'je were created, and they swiftly and bloodily won the Bretheren the war. After being unleashed onto the battlefields, the Sa'fao'je sometimes could not be recaptured, and so some still skulk through the corners of the Salt Desert, wreaking havoc as they go.

The most fearsome of the wartime Sa'fao'je was the Rai'kă'pę (God Worm), formed from the bodies of no less than fifty Children of Blood near the end of the war. Upon its creation, Çao'sana himself offered his body to it; according to Ai'sana, the worm drained him of all his blood, then sprouted a new face and arm resembling his and left the old body to crumble. The Bretheren released the worm during the final, decisive battle of the war; it crushed and devoured every last warrior on both sides within seven minutes, then burrowed into the ground and disappeared.

The Rise and Fall of Ai'sana

Ai'sana, after witnessing the death of her brother and the end of the war, opted to alter their research and move away from transmutation. Citing how the Rai'kă'pę devoured Çao'sana's blood but left the body, she theorized that blood may be a more pure carrier of power than the combination of blood and body. Using the blood of the prisoners of war, she began research anew.

Soon enough, Ai'sana discovered a method to magically distill blood into its purest power-giving essence and mix it with her own within her body, elevating her own power. She and her closest followers repeated this experiment again and again, until there were no more bodies to be easily drained.

Here, Ai'sana was stuck for some time, until she discovered another method; one by which she could distill any being which lived in the eyes of the gods into its purest life force, dissolved in the solvent of blood, even if blood did not run through its veins. By this method, her power grew without bounds, until, by a great ritual, she consumed every living being in the Dead Fields at once, leaving behind only husks which were ground by the wind into a poisonous salt. The Amalgams and Sa'fao'je were spared, not being living beings in the eyes of the gods; though they carried blood, it did not flow, but instead congealed inert in their veins.

Following this ritual, Ai'sana and her followers confronted the gods, demanding a seat among the divine once again as beings risen higher from the Zahar. The gods cursed them, spat on them, cut them down and doomed them to undeath; as a cruel joke, they were allowed to keep their power, but prevented from ever exercising it, instead forced to lie dormant within a corpse, blood ever churning through magically preserved veins, gazing through rotting eye sockets. Due to the sheer concentration of life within them, they could not bleed out, and so instead spilled blood eternally, staining the sand red, until eventually discovered by the Mukasa Peoples.