I've been working on a map with the new Obsidian and brimstone combination. On my latest play test, I found that on this four player map, the three A! underlords, all set to "hard" with random personalities, do not deal with the new terrains at all. I have destroyed two of the other three dungeon cores myself, with only workers fighting back. The AIs did not open up any of the areas, which contain Empire enemies for conversion and fighting. I used the sight spell on the fourth core, and it appears to be the same.