Board Thread:Warhammer 40k General Discussion/@comment-24821739-20140604204305/@comment-6078851-20140605151258

personally i can envisage no scenario in which the imperium of man survives, let alone recover. when the throne fails, that's when and not if, emps' clogs get popped, astronomican goes out, earth's overrun by daemons, intersteller communications and travel become an infinitesimal fraction of what they currently are, and the empire crumbles. humans would survive though, no doubt, but galactic reign would now be beyond them.

if, however, emps comes back, and there's a few choices for him: shamanic reincarnation is one but he's also, supposedly, a perpetual (i only learned of perpetuals a couple of months ago and they seem to be actual immortals and not the virtual immortality of astartes. vulkan is a perpetual and was beheaded, whereupon a day later he'd grown a new head that was exactly the same as his old, and recently separated, head.) if emps is a perpetual (of which there seems to be very little information, but he doesn't seem to know he is) then he'll be up and at 'em within 2 days of the throne failing. earth would still be overrun by daemons but i'm pretty sure emps would be able to clean them out. and still the imperium of man wont survive: the imperium is almost the polar opposite of what emps wanted, so if he returned i think the 1st thing he would do would be a complete overhaul of the imperium's heirarchy and policies. it might still be called the imperium of man but it would be a different empire (at least i hope that's what he'd do).

it is officially mentioned that emps is more potent a psychic force post-corpse than he was pre-corpse, but if he's a perpetual then his physical body would be able to contain his psyche without burning out, because a perpetual's body can't burn out.

and if the astronomican is luring the tyranids then emps dying could be a good(ish?) thing: everything would still get eaten, only now earth wouldn't be target. but if emps comes back physically then the astronomican will be straight back on, and earth once again becomes the really bright shiny thing catching the hive mind's eye.

as for the whole emps battling the gods in the warp after the throne's failure, that's either an in-universe theory, or just a fan theory (it sounds a bit like the starchild theory), but a theory is all it is.