Tactics against Necromancers.

Yesterday, my friend and I were discussing tactics against a Necromancer who had gathered the Amulet of the Lich and somehow amassed around 20,000 Liches. We were considering Humans (as the opposing force) and concluded that it's possible to win such a battle if all your skills are at 99. In that case, you can summon Earth Elementals, but you need to be at least an expert in Earth and Air magic. And you need to get to the point where... when you finally kill the Liches, you need to restore at least one of your own units... but in reality, we'll be testing this today with real armies and real magic!... I'll report the results tomorrow. Oh, and the Necromancer supposedly has skills around 40...