I'd like to use that bit about chaos to say that the will of chaos could easily bend Space Orks minds towards its own means I dunno why they don't try it.I think that the Imperium will eventually fall...by it's own design. Every empire eventually WILL fall. Either by the sword or the slow decay of time (stolen from LOTR if you didn't catch that). In the end, I think that none of them will really win. The Tau are going to be obliterated by the Tyranids, who in turn will stamp out most of the Orks before being destroyed by the Necrons, who, undoubtably being unable to control the Warp or the Eldar Webway, will simply go back to their tomb worlds, leaving the galaxy as it was before Man. Chaos vs. Eldar.
The real thing is the Tyranids will NEVER be able to conquer the universe, as ANY prolonged campaign against the Necrons will destroy them. Most of the Tyranid weapons require living flesh, and the losses suffered against the crons' would never be recoverable by the Tyranids due to Necrons being made out of metal. Also, Chaos will never die. You can't kill an idea, after all, so even if EVERY chaos worshipper is killed (nearly impossible, as many live in the Eye of Terror, where no mortal army would ever last a day), the Chaos gods, faith, and Demons will live on. Humanity itself will survive, but the Imperium as a whole will die. Unless the Tyranids overrun the entire galaxy, or the Necrons get off the toilet and go to a full-scale war, nothing is going to come close to putting a dent in Humanity. But, as a nature, humans rebel against authority. I think that unless a second Horus Heresy were to give Chaos an unopposed shot at Terra, they're never going to win the Long War.
They have. There was a Khorne Ork army a while back, and a guy who frequents my GW has a Nurgle Ork list. Orks are simply so many that Chaos can't warp them all.I'd like to use that bit about chaos to say that the will of chaos could easily bend Space Orks minds towards its own means I dunno why they don't try it.