The “An Eye for an Eye” scenario.

The simplest option is to make Lethos the main hero (and move him to a supporting role in the scenario) and develop his summoning skills. While the Mistresses/Hunters are in invisibility, the Phoenix can decimate the enemy army. And Dark Magic isn't a burden – with "Berserk" and "Subjugation," the task becomes extremely simple (just find the Dark Magic spellbook).