Suppose the Nerevarine never showed up and Dagoth Ur completed Akulakhan. Aside from the obvious "Corprus spreads everywhere" answer, what might happen? Could we get a Dagoth-Ur equivalent of Talos? What are the metaphysical implications, if we go with the idea that Dagoth Ur's nega-CHIM spelled bad news for everyone, even guys like Vivec?

Everything would be destroyed and Dagoth Ur would nega-CHIM his way into the godhead

What I'd find an interesting scenario is if Dagoth Ur won, what would happen 200-odd years later when Alduin returned and the Dragonborn was (meant to be) born. Would he have corprus? How would that affect the whole end-of-the-world thing goin' on?

A bad case of food poisoning that would lead to the next kalpa never ending.

Edit: Also, wut? My avatar reverted to something I had daaaaaays ago.

The avatar of Akatosh would have fought Akulakhan instead of Mehrunes Dagon.

That's assuming Akulakhan didn't steamroll over Cyrodiil and that Akatosh is able to defeat it, Mehrunes Dagon isn't the most powerful Daedric prince hell it's said he is one of the weakest.

We are all assuming, here. Yes?

The point being the Avatar of Akatosh had a hard enough time beating one of the weakest Daedric Princes, what makes you think it could beat a giant brass golem with the heart of Lorkhan?

Is this even possible?

Possibly, I'm not all that great at metaphysics.