Undead army

[Jamers]

I agree with ganjatron; I just passed Demonis and my army was:

Inquisitors
Knights
Hunters
Black Unicorns
Archmagi

I found that the Black Unicorns (particularly with the Inquisitors' Holy Anger or whatever [bless]) did immense damage to the demons. They have a large gap in their base damage (12-21) so the bless really benefits them more than most units. The Horn of Light ability wrecks demons and undead.