looking for tactical advice

[st.patrik]

Other undead-only spells include:

Cleansing Water [Evocation 6, 2W to cast]
Solar Rays [Evocation 2, 2S to cast]

Neither are incredibly powerful: Solar Rays never affects more than 1 grid square, and Cleansing Water has low base damage (though it is armour-negating).

I personally have found it very hard to dominion-kill in the way Taqwus describes - maybe I'm doing it wrong.

You don't mention what nation or age you're playing in, although from the Jade Emperor I suppose it's T'ien Ch'i. If so you don't have assassins, which otherwise might work (if properly equipped).