I'm somewhat new to 40k and I've been reading the Black Library books. It's seems like a good way to get started. Then I realized there were countless other races, so I'm slowly learning about those, too, through Wikipedia and these forums. Anyway, I have a question about the emperor and the chaos gods concerning the limit to their power.

I know the Emperor destroyed Horus when he was broken and wounded. This apparently caused the chaos gods to recoil in terror. But take this hypothetical... If the Emperor were to fight the chaos gods with everyone at their full potential, who would win? If 4 gods against 1 man is unfair, then make it the Emperor vs the strongest Chaos God.

Any information on the limits of their respective powers would help too, like if the Chaos Gods actually do fight. Thanks.