Shas'O Kais
The hero unit of the Tau campaign in Dawn of War: Dark Crusade, Shas'o Kais (who, according to developer commentary, is really the Kais, the protagonist of Warhammer 40,000: Fire Warrior) is the textbook Noblebright in a world gone Grimdark. One of the only commanders in the entire campaign willing to negotiate and talk common sense, Kais is nonetheless exceptionally manly for a Tau, and proves he can get shit done.
The fact that he's the most merciful commander in the setting does not stop him from getting a body count in the thousands. Though he's unique in that he's willing to use diplomacy first, he's just as hard-edged if that fails, and is more-than-willing to rely on Ambassador Plasma Rifle to come to a resolution afterwards.
He's a hell of a lot less of a dick than Commander Or'es'Ka.
Service in the Dark Crusade
A fire caste commander who is an inspiration to his men, Shas'o Kais rose from the rank of Shas'la to his current position. A student of the Tau Commander Puretide, who led the Tau forces that originally took Kronus from the Imperium in the first place, Shas'o Kais was brought to the world to (hopefully) mimic his forebear's great feats, now that Kronus was being ravaged by six other goddamned fucking power groups. With a secondary duty of keeping the Tau Ethereal, Aun'el Shi'Ores safe, the Tau occupied the planetary capital and made ready to slowly take the planet back for the Tau Empire.
Kais did some major damage during the Dark Crusade, and was rather infamous for the damage his forces did to the Orks and Eldar during the war, and they engaged in some truly bitter fighting with Governor-Militant Lukas Alexander's men. Unfortunately, Kais' forces did not count on the aggressiveness of the Blood Ravens Space Marines under Davian Thule, and Aun'el Shi'Ores was assassinated. With the Tau leader dead, the Tau war machine broke ranks when morale plummeted; Kais gathered together the survivors and got them out of the system, marking him as one of only a handful of commanders to survive the Dark Crusade.