The chaos gods have many traps. Even the Death Guard only turned to Nurgle in desperation (they were trapped in the warp and dying).



That is the danger of the powers of chaos, they embody our darker impulses, rage, despair, desire... I've often refered to them as the four horseman (Khorne as War and Nurgle as Pestilence are dead give aways, Tzeentch would be Death, as that is the ultimate change, Slaanesh would be Famine (might seem strange, but it's followers seen to try and fill a void/hunger they can never still...).



A note on chaos though, it does have the power to expand a lifespan. Becoming a daemon prince might be very tempting for a frail bodied short lifespan individual (remember chaos goblins?)

One day a Tau will fall. He/she will not bring down Tau society, as the corrupted individual will most likely be put down quickly by it's peers, but it might happen.

(an excuse for a Tau vs. Tau battle?)