Advice on Spellcaster Necro build

[Wyrm]

Have a merc or other ally make a kill and then ACE 'em (Amp and Corpse Explosion). Even if one CE doesn't kill the group it'll cut them down quite a bit and make the next kill all the more easy for your merc.

You may want more than just the base point in Dim Vision, unless you have a lot of +all skills items, to make the ranged attackers in Hell a bit easier to manage.