You take Arache, level her up to 4, and clear all the maps without any losses using a single stack of a hundred units (you can even use main creatures). With a hundred units, Arache will give you a Drain Life skill of 1500 percent.
The only problem might be with the Necropolis.
Overall, interest in the game has dropped dramatically. I'll try playing without any dynasty weapons at all. Or I'll take a break.