Defeating Ashen Ermor?

[Micah]

A simple defensive thug that can last until the auto-rout kicks in will annihilate any number of attacking mindless undead as long as their leaders don't magic you to death.

A lucky wraith lord with a vine shield and some extra prot and regen should be able to just stand there and soak hits for 50 turns IIRC...the AoE weapon is only useful for attacking provinces. Golems are a bit iffy in this role despite the 0 enc since they tend to collect afflictions since they can't be given regen or heal during the fight, but the idea is the same.

And firstorm is much more effective than wrathful skies for undead clearing, unless Ermor is rocking Army of Gold.