The mission wasn't actually difficult, but rather tedious and long. On the other hand, it was on this map that I leveled up Markel's stats and skills quite well.
By the way, this time I didn't even try to complete the secondary task of collecting 1000 skeletons; they accumulated on their own:D

Yes, and to be sure, I also turned the contents of the knight's castle into undead. First, I maxed out Markel, and then I only sent Isabel to take over the garrisons and the last castle. And I gave her an army of undead and two artifacts that increase the experience gain percentage, because otherwise she might not have leveled up enough. But as it was, she reached level 26 without any problems. But, of course, an undead army is more effective with a Necromancer than with her, but that's just a detail and a matter of taste and preference, depending on when and how you level up your heroes.:smile33: