[Shovah32]

If you can get a high death mage(preferably 7 or higher), perhaps with a communion or your pretender, shadow bolt can get insane. If you also give the caster a spell focus, eye of the void(assuming he has enough precision to take the hit from losing an eye), skullface and runesmasher+shield or a skull staff then things get... fun.

The damage, AoE and range and penetration(I think D6 gives +2 penetration and D8 gives +3) all scale nicely, so if you end up with a D7-D10 caster you can decimate any non-undead without insane magic resistance. And if you happened to use it against massed ulmish infantry... any square hit would end up empty.

D8, spell focus, eye of the void and runesmasher grants +8 penetration. Anything that survives that must be either undead or have crazy MR. That's the point at which you pull out wither bones and drain life.

This works great with skelespam too, as they are immune to friendly fire from this spell.