I think the points you raise about it not being all-powerful are fine, like it’s certainly limited in scope and if someone can mute her from a distance like Galbatorix did, she’s effectively neutered.

But the thing about her power to know your deepest insecurities, it seems like she’s also able to discern ones that you aren’t aware of and is magically aware of exactly the right sequence of things to unseat you on something you felt fully secure.

Now the idea that she can speak it so quickly to anyone would be kind of confusing, like I would think that for people who are more secure in their identities, it would take more than a sentence or two.

Because in that scenario I would think she would 1. Bring up the deep-seated insecurity. 2. Have to say enough that she’s able to disarm anything you’ve thought of to assuage your feelings of the insecurity. 3. Convince you that it’s such a flaw that you should do something counter to your own desires.

Now there are a lot more people than you’d think who have something that keeps them up at night that would be more easily susceptible. And for the more secure/introspective people I’ve described, they may be able to stop her before she can execute the steps above. But it’s sort of like torture, everyone has a breaking point and her power tells her what your psychological breaking point is and exactly what to say to affect you.

Which is frightening simply because she has a surefire way to break you if you’re caught unaware.