I had given up on turning way back in the Vale of the Shadows.
I tried it again last night when Lord Maluradek summoned about 15 skeletons. Sure enough my 27/22 C/R could destroy 5 of them at a time. Sweet! Since my paladin reached level 30 a while back, I should have tried using him in the crypt. Maybe even santuarying him, for extra cheese.
I've been handling the spectral guards using tried and true spelltrap/killzone and summons as meat shields techniques. Along with peppering them with ranged weapons while trapped. Tedious and a bit slow. I should really start taking advantage of all the damage immunity equipment and shapechanging. Good idea!
I wonder if they can be turned?