I have encountered several types of Wildlands including the Imperium ruins, the Plaguelands swamp where Morian the Ruin of Summer lurks, and the Dragonslayer area. I have yet to finish any of these, though not for lack of trying.
I the Imperium, I defeated everything, but you can't found a city in another kingdom, and you can't get rid of the Imperium "Kingdom" without building a city in it (as far as I know).
In the Wildlands swamp, I checked it all out and ran away from Morian only to have a computer finish the quest (I assume; the "Kingdom" of the swamp went away). The computer never killed Morian, so I had to put it down when it came for one of my cities, but it was unclear what I was supposed to do to finish the quest and unlock the area. I assumed you had to kill Morian, but seemingly not.
As for the Dragonslayer guy, he sits at the back of a canyon behind a gate. However, I cannot get past the gate to fight anything. I suppose I could try to Lower Land to get in the back way, but that seems like cheating (and requires Earth Magic). There should be a quest or something to unlock the gate.
The fact is though, that these areas are really only good for 1 thing: XP. Even when the swamp was cleared by the AI, all I could build was an extremely mediocre city in the middle and get 1 elemental shard and a gold mine (plus some monster bases that it won't let me build). That's not more resources than the area would probably have if it were like the rest of the world. Even the Imperium area had only 3 shards, 1 food and 1 ore mine, which is not bad, but not particularly great considering how well guarded it is and the size of the area.
When I do a ton of work and clear out some place full of big baddies, I would like to get some good rewards out of it besides the XP and loot. Wildlands should offer significant resources or great city tiles (4-4 or even 5-5 tiles?) or *something* strategic to compensate for the time my sovereign/champions spend clearing them so that I don't think of them just as XP banks. How to actually "win" them should also be a bit clearer (or more possible).
