[Soyweiser]

After Blood nations reach blood 9 teleporting raiders die like flies. The banishment spells and life for a life take care of most of them. The research window where you can actually tele raid blood nations is very small. And small groups of hidden troops can also get killed by imp spam.

And if you lack the blood levels to go for the higher level ones, enough sabbath slaves give you higher levels. Blood is super strong as a magical path.