The "Warlords" scenario.

It often turns out that you don't have time to develop properly, and the computer already controls the other seven castles. And then, as you can imagine, you're left with a very difficult defense. Also, the AI sends weak units to patrol the center of the map, where there are several mines, and they gradually gain levels. In any case, I didn't finish it and gave up. (I was playing as the Necromancer, with the main hero Lucretia).