Shas'o Tash'var Ol'nan B'kak, often referred to as O'var, which translated from the Tau Lexicon into Low Gothic means Commander Brightsword, was a Tau military officer and a student of Commander Farsight and the commander of the Tau outpost world of Es'tau. Following the Second Phase Expansion of the Tau Empire, Brightsword led the Tau forces against the Imperial forces attacking the world of Nimbosa. During the initial assault, he annihilated the 9th Vostroyan Firstborn Regiment at the battle for Polia. When the Imperium counter-attacked, Brightsword wiped out the first invasion force at a battle remembered amongst Imperials as the Koloth Gorge Massacre. As a result of his unusually brutal tactics in contravention of the Greater Good, he was recalled back to the Tau homeworld of T'au and the world of Nimbosa was reconquered by the Imperium shortly after. He was assassinated by the 13th Penal Legion with the help of some members of the Tau Water Caste who feared his aggression would spark an unnecessary war with the Imperium of Man.
- Cities of Death (4th Edition), pp. 56-57
- Codex: Tau Empire (4th Edition), pp. 14-15
- Last Chancers (Novel Series) by Gav Thorpe