Just a little bit of maths correction: The basic fear spell will be much more effective than you mentioned (lvl 38). I expect that your calculation was: the base level 9 x 2 (because of dual casting) +10 kindred mage + 10 aspect of terror. It's wrong. Twice.
1: dual cast multiplier is 2.2.
2: dual cast affects the bonuses from the perks so: (10 +10 + 9) x 2.2 = 63.8 (!!!!!).
That means this spell will affect almost any enemy in the game even a lvl 58 briair heart.
Just a little bit of maths correction: The basic fear spell will be much more effective than you mentioned (lvl 38). I expect that your calculation was: the base level 9 x 2 (because of dual casting) +10 kindred mage + 10 aspect of terror. It's wrong. Twice.
1: dual cast multiplier is 2.2.
2: dual cast affects the bonuses from the perks so: (10 +10 + 9) x 2.2 = 63.8 (!!!!!).
That means this spell will affect almost any enemy in the game even a lvl 58 briair heart.