Quote Originally Posted by Gavinfoxx View Post
How do you influence the Tau to do something, though, as Chaos? I mean you could do something to the human population in their Empire, but that sort of thing is already being done by Chaos...
This. You can't influence the Tau leaders directly. The best you can do is try to agitate the Gue'vesa population and make life hard for the people in charge of running them. So, business as usual for Chaos. You can amp it up a little bit, focus some effort on it, but that's very likely to attract the Culture's attention (they're pretty good at finding Chaos Cults by this point) and that's going to totally backfire on Chaos, because there's little better at bringing people together than finding out that their enemy is trying to drive them apart.

Short of direct and total intervention by the Chaos Gods (which could basically do anything), the Tau are a very difficult nut to crack right now. They also aren't very important to this struggle in the long-run, barring what's already been done. At most, agitate things a bit to maybe sour relations to some degree, and focus on the Eldar, Necron and Imperium fronts where some sort of success might actually be achievable.