I've been trying to train up my blue way stat by using freeze on rats in Ojaveda. Usually, these spells were taking about 25 m.stamina points per cast. Yesterday, after 20-25 spells, they were taking 250 points. Today, it was over 400! I was casting at 0% power. Boosting to 100% used the same amount of m.stamina. Once this happens, any spell I cast uses the same energy. (I only have a few realm 1 spells). My stats: AGI-25, CHA-80, END-60, INT-110, STR-50, Will-85, Blue Way-16.
I tried with another character and was able to get from level 6 to level 9 in azure using defensive wind without a problem. I also did some rat hunting with freeze and cast about 25 spells with no problem.