Join Date: Mar 2009
Location: Staffordshire, UK
On a serious side Tyranids then Necrons nuke them.
Nids devoured flesh and all sorts and their size is beyond gargantuan. The imperium sure as hell don't have something to stop a single hive fleet short of bodies which aren't entirely infinite. And at best throwing men and arms is really out of desperation not tactics and method. Orks can't exist without planets to grow them so that's out.
You could are that Chaos as an entity would still be around but the 4 gods don't give the much of a damn right now.
Though really Tyranids won't consume Cron as far as I'm aware so then the Crons just need to exterminate the 'Nids once they have consumed all the biomass and starts to die of/unable to grow.
That's always been my understanding of the Universe at least.
Even if both Eldar did hide in the webway they would die out sooner or later.
The Old World just became a fart in the bath.....