User blog comment:Raffney/Timetravel in 40k OR is the Emperor a Chaos God?/@comment-8881468-20180224204647

erebus only showed a vision in a dream provided by chaos, the Wb did not use time travel

in all 40k lore I can only remember 2 instances of that happening, the ahriman novels and desert raiders

as for emps: he is not an amalgamation of emotions in another deímension, he is not, will not and never was a chaos god, nor is he powerful enough to be that