Yeah, Mikko's got the long and short of it; the Crystal Tower was basically a giant solar panel and battery. It wasn't a last-minute addition to the empire, but wasn't exactly there for a lot of its timespan, and a lot of the reason it's important to the game world got tacked on at the end. Also, we now know what a tower sucking up ambient aether looks like and what effect that has, and it's not Mor Dhona.

It's important to remember that the Allagan Empire wasn't exactly a ten-year thing. It lasted for goddamn centuries, it's just that most of our knowledge of it and most of the present-day meaningful events surrounding it happened at the tail end. There's a lot of stuff going on there.

Although speaking personally more on the subject of the thread... I feel like exploring more of Allag isn't interesting to me without either time travel or going further afield. We've explored Allagan ruins in their ex-heartland quite a bit; I think to make going back to them interesting, we either need to go back to when they were alive and see what that's like (we actually know pretty much nothing about the lives of the general Allagan populace), or we go off and find out what Allag was like judging by the ruins in somewhere like Ilsabard.