I think I saw you post earlier there was some kind of conflict with Lycanites mobs?
As I posted before I heard the Trent hitting the player could cause world corruption because of a debuff it caused...wonder if that was because there was a conflict with potion effects from blood magic?
I talk about the config changes both to metallurgy and to Blood Magic in this video. I also posted the text in the description so you can copy and paste if you want to modify your own files.
I'm not sure this will fix the Trent issue. That one puts a status effect 0 on your player which Minecraft thinks is invalid and then crashes. You can fix it by changing it to status effect 1 with an NBT editor. It'll be in player.dat on a server, or level.dat if you're in SSP. I guess it's possible that changing the Blood Magic values could fix it, but I'm not sure they will.