I haven't noticed any change in my elf blood from Sanguine, though maybe its all in my head. If its working, any chance there could be an echo when it fires on Exsanguinate?

Also, could there be an echo when a mob is "too willful" and impossible to enslave as the helpfile implies? I've found some interesting mobs I want to enslave, but fail everytime. Not sure if its just bad luck or if they just won't be enslaved.