Well, Warlocks also have a high initiative, so perhaps the Furies will manage to destroy the Imps. Demons only excel in attack, and their defense is simply laughable (as is the case with Dark Elves). I would play as Iranna (education, mana attraction - one of the defenses against mana drain), spellcasting, summoning, attack, defense, or luck. Don't forget to create Phantoms of the Furies. Another option is Lethos, dark magic (mass slowing and weakening will be a very unpleasant surprise, especially for demons)...