My wraith does well against the DF until he gets swamped by the other things around. Cutting bones would help against them, I'm sure. On the other hand, I often miss that bones have been thrown and act surprised to find two lich lords and 3 rotting corpses waiting in line to kill me.
The I run off, kill off the extra spawn and work on the DF for another half minute until I have to repeat the process. It's a long and tedious process which I've done all of once before deciding that Doom is a 2 player minimum area.
So the skills you need are bushido, parry, weapon skill, and lower levels of spirit speak, chivalry (EoO is very important against everything except the DF) and some necromancy jewelery (necromancy isn't required, just the jewelery). The last one or two skills are flexible. I chose to have high necromancy and tactics. I've also used focus and tactics or anatomy and tactics.
