I am very interested in using the frenzy spell as a stealthy mage so I can get my enemies to kill each other off. Right now I have the dual casting and kindred mage perks. As best I can tell, a dual cast frenzy spell with these perks should get me to level 43. But I am not sure if I am calculating this correctly. Falmer Warmongers are level 48 so by my calculation my dual cast frenzy would not work on them.

Before I waste a whole bunch of perk points to get the Rage perk, I would like to know if my calculations are correct.