Discussion about Dungeon (Dark Elves).

I still haven't quite figured it out myself... At first, I thought that units with earth should be attacked with air, those with fire with water, and vice versa. But my observations show that any element can attack any other. And I think I've figured it out: it should be a unit with the opposite element. Which elements are opposite to each other? And does the chain of elements affect the hero's magic?