Magic in Heroes of Might and Magic V.

It's not as effective as other spells, but at the same time, it doesn't allow the Orc to be idle. IMHO, of course.

I don't think it's significantly less effective than other spells. Firstly, to learn "Scream," you don't need to level up the main "Scream" skill, unlike learning the 4th level of "Chaos," which requires leveling up the "Chaos" magic. Secondly, "Scream" cannot be weakened by magic resistance or other debuffs. And finally, in different situations, "Wrath of the Horde" can kill more enemy units than, say, the Warlock's "Earth Shock."