“Zsaekriel, at our present predicament, we are in need of a new Field Marshall. In the late Field Marshall Ras Algethi's journals, he mentions you a lot, and was training you on the side to become a commanding officer for the Imperial Guard.”―Bellatrix La Rouge to Zsaekriel Dtoahfre'Vuun, shortly after the Ambush on Lehon[src]
Ras Algethi was the Field Marshall of the Imperial Guard, Luthor Elyurius' personal guard. After the Sith Insurrection that toppled the Elyurius dynasty from the Empire, Algethi joined forces with Knight-Commander Iona Peller and her Imperial Knights-in-exile. He fought during the Ambush on Lehon where he was killed by Stern Stark.
He was eventually succeeded by Zsaekriel Dtoahfre'Vuun.