KonServator is right about summoning. I recently played as a Warlock in Heroes of Might and Magic, using summoning against Orcs. The Orcs, even if they do summon units (which is rare), create chaos. I also focused on attack and defense, resulting in a powerful combat mage who completely crushed the Orcs in the early second month. But what really stands out are the mines. They deal insane damage; only 15 unfortunate warmongers made it to my warriors, and all the cyclops (there were 8 or 9, as there were 3 Orcish outposts on the map) could only reach the middle. There were no problems finishing off the remaining shamans and centaurs. Overall, I was very impressed, and I think I'll experiment more with a warlock focused on summoning.