Originally posted by OctoberSky:

Please double check my math[valheim.fandom.com] but to get level 40 blood magic your skeletons (I assume 2?) have to amass nearly 3K hits while level 60 requires nearly 8K. Level 80 is phenomenal with 16K hits. No easy thing and I was feeling pretty smug at level 36.

You can give your skeletons a shield, and when their shield is destroyed, it counts toward your blood magic skill as well