Necropolis versus Academy.

Even without Battle Protection. The main thing is that there are many of them, and at least a few (especially if the Necromancer doesn't have high intelligence) can cast Armageddon. Five or six Armageddons, and what will be left of the army? So, I think this is one of the effective strategies. You can also use Swiftness and Shock or Freezing Touch. You can't defend against everything.