That's also another worry of mine though; the fact that it will become obsolete after I level up.
Shouldn't be a problem if you get the "higher level opponents" perks. I only have
Kindred Mage, but no one can see me and they lose me if I cast Invisibility right in front of their faces.

And as I read the description for Kindred Mage it should stack with Hypnotic Gaze, Aspect of Terror, and Rage. I'm sure you'll have to get the higher level spells, but I'm pretty sure the spells will work on high level targets.
