Yeah, it's pretty clear that Firwarrior was demonically empowered by Khorne. There's a reason he's standing on a mountain of skulls on the cover for the game.
doesnt make sense tho as the chaos forces in the game would obviously be empowered by the Gods (Tzeentch most likely) and Tau arent affected by the Warp quite so much as humans and eldar
Kais is weird for a Tau-his fellow Fire Warriors are terrified of him. And Kais took the whole 'Fire Warrior' thing just a bit too seriously, and managed to burn bright enough in the warp for Khorne to notice him. Warpsmith-just being Chaos doesn't mean you're empowerd by the gods-that's reserved for only the highest ranked, and Kais had Khrone giving him limitless power, and actually talking to him directly (ofc Kais thought he was just going mad). After all, the first of a race to fall to Chaos will always be more interesting than run of the mill Chaos marines.
Tau are perfectly capable of being fucked six ways to sunday by Chaos if it is willed on a whim. The lucky thing for Tau is that their souls are pathetic compared to those of humans, and thus are almost invisible compared to the raging inferno of Eldar and Humanity. However there's not reason why Chaos cannot simply pluck a Tau soul and empower it... or crush it. It's just a matter of attention.
