Chaos magic. Is it necessary?

You can apply any spell to a ballista that can be applied to a magic arrow:). Yes, yes... it will mow down almost half the army! I can't imagine what will happen if you develop a mage, and have a sworn enemy, and then cast, for example, Chain Lightning, or Ice Ring, Meteor Shower:D, or some kind of Earth Shock - I know, I know, this is a perversion, but how many troops will fall!