Kavalanera Brassanas was a Knight Abyssal of the Sisters of Silence. By M32 during the War of the Beast, she was one of the last surviving members of his order, exiled to the world of Nadiries. Commanding Purgatory Squad, like the rest of her order on Nadiries Kavalanera Brassanas expressed great disdain towards the current Imperium but was nonetheless convinced to aid it against The Beast after Lord Commander of the Imperium Koorland revealed that he had the blessing of Vulkan himself.
During the second and third Imperial offensives on Ullanor, Kavalanera led her Sisters in the ritual to use an Ork psyker to create a "reverse Waaagh!" effect to slay The Beast. During the third battle, the ritual succeeded and one of the "Prime Beast" Orks was slain.