It is irrelevant to say that you have to level up blood magic for the skeletons to be useful. Time to level up the skill, the game is already over. I did the greydwarf spawner technique. I let the skeletons kill them for almost two hours. I'm barely past level 20 in blood magic. And the skeletons aren't much stronger...

The skeletons, as they are, are useless, indeed. Summoning them consumes too much eitr and health. The best in my opinion is to mount the blood magic with the greydwarf spawner technique for the shield and drop the skeletons...