In the Creation War, Ares battled Bryakus in the wasteland Felbarum. In this epic combat, Ares severed one of the necks of Bryakus. This drove Bryakus back into Anaz, forcing him to retreat through a intra-system rift back to the moon Bingatho. The first hydras sprang from the blood spilled by Bryakus at Felbarum. Explorers of this area say that Bryakus's severed neck still lies there on the slopes of Anaz, and that it sometimes bleeds, giving birth to more hydras.
When the primordials invaded Throndar, Bryakus proved the greatest threat. Balthioul and his solar wife Hamaliel, the world's top Covenant defenders, went after him. By the time they reached Bryakus where he was cutting wide swatches through their Eenkai and angelic army, Throndar had been stripped of its link to the Web of Magic. Without the ability to use magic, the two became victims of Bryakus's many bloodthirsty heads, perishing on 12 Lunar 8337 DE.
Bryakus lives on Bingatho, a moon of the world Marragh, and is in all likelihood the moon's apex predator. He is so big that he looms over hills and treetops, forced to always be on the move for want of food. When prey is scarce, Bryakus is forced into a state of hibernation that can last years or even decades.