So, I was reading through the Rising Threat series and a thought kinda hit me, right around the part when Crystal-Like-Law falls. With that series, we have three reports about what happened in the Oblivion Crisis, with the previously known events from Oblivion, and Dagon kicking the Dunmer where it hurts, as he had some scores to settle with them.

In the first Aldudagga, it's stated that Dagon's long term goal is to destroy the bits and pieces he's added from previous kalpas, in order to let Alduin keep chomping up the world. And since Alduin did come back, Dagon must've succeeded. If he'd failed, coming back would be an exercise in futility. So what did Dagon destroy? Kvatch? Nah, that was only spread around a bit. Still same bite size for the dragon, only minced and puréed. The Septim bloodline? No, that was already expected to be done once he made his entrance - also not something from previous kalpas (especially since Talos was unanticipated). However, according to Rising Threat Crystal-Like-Law fell - sure, only one source, but I see no reason to doubt it, and had it not been for Martin Septim's unexpected field goal in the sudden death round, White Gold would quite likely have fallen too.

Now, also in the Aldudaggas, it's hinted that the Leaper Demon King that became Dagon is Magnus. Now, as far as I know there is no consensus on this, but bear with me. Magnus is universally known as the architect of the world, who fled creation and supplied the world with magicka in the process. Since we know that towers are needed to anchor a world, could it be that Magnus' input was the blueprints of the towers? That the bits and pieces from previous kalpas was the tower designs? Either by copying Aka's spaceship or by giving him the driving lessons for it. It would then be natural for Dagon to target as many towers as possible. This would in turn lead up to Magnus' departure not being him fleeing, but rather an intentional move, gassing up and kickstarting the anchors by supplying a steady stream of creatia.

I did a couple of quick searches on this but didn't see anything from earlier. But then again, I've been inactive for the last year or two, so might have missed if it's been brought up before.

For convenience: http://www.imperial-library.info/content/skyrim-rising-threat - http://www.imperial-library.info/content/fight-one-eating-birth-dagon