Whew, this Empire is huge! I have collected memberships in 47 cults, and that wasn't even as many cities as I visited; some towns had missing or deceased priests, some had priests in churches I was already a member of. But in the course of this trek, I got a view of the big picture:
I come from the only surviving elven nation. Most of them died out within 50 years of history, some from rampages, some gone within 10 years of coming into contact with another nation. My people, I'll call them the Swift, survived rampages and existed for 800 years on the border of the biggest human Empire around. In fact this Empire, I'll call them the Fruity Feds (the name alone is reason for them to die,) rolled over everything else in it's path and left it all in ruins, until it hit the border of the Swift and it could go no further (you shall not pass!) They got one flickering square into the Swift, and it stayed that way for 800 years.
The only other elvish settlements around are in the Fed's closest competitor, the Sol-Talons for short. They were all gradually absorbed, and though I doubt it was a bloodless takeover, those retreats still have their own local governments and are thriving today. There isn't a single ruin in Sol-Talons, all cities were incorporated intact, which makes them look like the most likely ally to bet on. Though they worship a titan I may one day have to kill, at least their law-giver isn't a demon.
But the Fruity Feds aren't at war with them, they're still fighting rebellion from a few cities they already occupy and surround. I expect those people will give me the funnest jobs after I kick off holy war. And I'm still intensely curious to find how the warlords of the Fed will react to me capping their ruling fiend after I've done them all so many favors.